31909802157 has 12 divisors (see below), whose sum is σ = 46333257984. Its totient is φ = 21161822280.

The previous prime is 31909802153. The next prime is 31909802161. The reversal of 31909802157 is 75120890913.

It is an interprime number because it is at equal distance from previous prime (31909802153) and next prime (31909802161).

It is not a de Polignac number, because 31909802157 - 2² = 31909802153 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31909802153) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9279783 + ... + 9283220.

It is an arithmetic number, because the mean of its divisors is an integer number (3861104832).

Almost surely, 2^31909802157 is an apocalyptic number.

It is an amenable number.

31909802157 is a deficient number, since it is larger than the sum of its proper divisors (14423455827).

31909802157 is a wasteful number, since it uses less digits than its factorization.

31909802157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18563200 (or 18563197 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 31909802157 in words is "thirty-one billion, nine hundred nine million, eight hundred two thousand, one hundred fifty-seven".