131097209 has 2 divisors, whose sum is σ = 131097210. Its totient is φ = 131097208.

The previous prime is 131097199. The next prime is 131097221. The reversal of 131097209 is 902790131.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84584809 + 46512400 = 9197^2 + 6820^2 .

It is a cyclic number.

It is not a de Polignac number, because 131097209 - 2⁴ = 131097193 is a prime.

It is not a weakly prime, because it can be changed into another prime (131097259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65548604 + 65548605.

It is an arithmetic number, because the mean of its divisors is an integer number (65548605).

Almost surely, 2^131097209 is an apocalyptic number.

It is an amenable number.

131097209 is a deficient number, since it is larger than the sum of its proper divisors (1).

131097209 is an equidigital number, since it uses as much as digits as its factorization.

131097209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 131097209 is about 11449.7689496339. The cubic root of 131097209 is about 508.0009002919. Note that the first 3 decimals are identical.

The spelling of 131097209 in words is "one hundred thirty-one million, ninety-seven thousand, two hundred nine".