115431209 has 2 divisors, whose sum is σ = 115431210. Its totient is φ = 115431208.

The previous prime is 115431187. The next prime is 115431271. The reversal of 115431209 is 902134511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88360000 + 27071209 = 9400^2 + 5203^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115431209 is a prime.

It is a super-2 number, since 2×115431209² = 26648728022403362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (115431809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57715604 + 57715605.

It is an arithmetic number, because the mean of its divisors is an integer number (57715605).

Almost surely, 2^115431209 is an apocalyptic number.

It is an amenable number.

115431209 is a deficient number, since it is larger than the sum of its proper divisors (1).

115431209 is an equidigital number, since it uses as much as digits as its factorization.

115431209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 115431209 is about 10743.8917064535. The cubic root of 115431209 is about 486.9014652223.

The spelling of 115431209 in words is "one hundred fifteen million, four hundred thirty-one thousand, two hundred nine".