157806931 has 2 divisors, whose sum is σ = 157806932. Its totient is φ = 157806930.

The previous prime is 157806919. The next prime is 157806941. The reversal of 157806931 is 139608751.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157806931 is a prime.

It is a super-2 number, since 2×157806931² = 49806054943277522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (157806911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78903465 + 78903466.

It is an arithmetic number, because the mean of its divisors is an integer number (78903466).

Almost surely, 2^157806931 is an apocalyptic number.

157806931 is a deficient number, since it is larger than the sum of its proper divisors (1).

157806931 is an equidigital number, since it uses as much as digits as its factorization.

157806931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 157806931 is about 12562.1228699611. The cubic root of 157806931 is about 540.3917265106.

The spelling of 157806931 in words is "one hundred fifty-seven million, eight hundred six thousand, nine hundred thirty-one".