197 (one hundred ndninety-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 196 and preceding

198 __NOTOC__ Year 198 (CXCVIII) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Sergius and Gallus (or, less frequently, year 951 ''Ab urbe condita''). The denomination 198 fo ...

In mathematics

* 197 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 ...

, the third of a prime quadruplet: 191, 193, 197, 199 * 197 is the smallest

that is the sum of seven consecutive primes: 17 + 19 + 23 + 29 + 31 + 37 + 41, and is the sum of the first twelve prime numbers: 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 * 197 is a centered heptagonal number, a centered figurate number that represents a

heptagon In geometry, a heptagon or septagon is a seven-sided polygon or 7-gon. The heptagon is sometimes referred to as the septagon, using ''Wikt:septa-, septa-'' (an elision of ''Wikt:septua-, septua-''), a Latin-derived numerical prefix, rather than ...

with a dot in the center and all other dots surrounding the center dot in successive heptagonal layers * 197 is a Schröder–Hipparchus number, counting for instance the number of ways of subdividing a

by a non-crossing set of its diagonals.

References

Integers {{Num-stub

In mathematics

See also

References