97 (ninety-seven) is the

natural number In mathematics, the natural numbers are the numbers 0, 1, 2, 3, and so on, possibly excluding 0. Some start counting with 0, defining the natural numbers as the non-negative integers , while others start with 1, defining them as the positive in ...

following 96 and preceding 98. It is a

prime number A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime ...

and the only prime in the nineties.

In mathematics

97 is: * the 25th

(the largest two-digit prime number in base 10), following 89 and preceding 101. * a Proth prime and a

Pierpont prime In number theory, a Pierpont prime is a prime number of the form 2^u\cdot 3^v + 1\, for some nonnegative integers and . That is, they are the prime numbers for which is 3-smooth. They are named after the mathematician James Pierpont, who us ...

as it is 3 × 2⁵ + 1. * the eleventh member of the Mian–Chowla sequence. * a self number in base 10, since there is no

integer An integer is the number zero (0), a positive natural number (1, 2, 3, ...), or the negation of a positive natural number (−1, −2, −3, ...). The negations or additive inverses of the positive natural numbers are referred to as negative in ...

that added to its own digits, adds up to 97. * the smallest odd prime that is not a

cluster prime In number theory, a cluster prime is a prime number such that every even positive integer ''k'' ≤ p − 3 can be written as the difference between two prime numbers not exceeding (). For example, the number 23 is a cluster prime becau ...

. * the highest two-digit number where the sum of its digits is a square. * the number of primes less than 2⁹. * The numbers 97, 907, 9007, 90007 and 900007 are all primes, and they are all

happy prime In number theory, a happy number is a number which eventually reaches 1 when the number is replaced by the sum of the square of each digit. For instance, 13 is a happy number because 1^2+3^2=10, and 1^2+0^2=1. On the other hand, 4 is not a happy ...

s. However, 9000007 (read as ''nine million seven'') is composite and has the factorization 277 × 32491. * an emirp with 79. * an isolated prime, since 95 and 99 are not prime.

In other fields

Ninety-seven is: * The 10-97 police code means "arrived on the scene" * The decimal

unicode Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 Char ...

number representing the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

lowercase "a"

References

Integers {{Num-stub