31907878957 has 4 divisors (see below), whose sum is σ = 32050963840. Its totient is φ = 31764794076.

The previous prime is 31907878949. The next prime is 31907878967. The reversal of 31907878957 is 75987870913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31907878957 - 2³ = 31907878949 is a prime.

It is a super-2 number, since 2×31907878957² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31907878967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71542107 + ... + 71542552.

It is an arithmetic number, because the mean of its divisors is an integer number (8012740960).

Almost surely, 2^31907878957 is an apocalyptic number.

It is an amenable number.

31907878957 is a deficient number, since it is larger than the sum of its proper divisors (143084883).

31907878957 is a wasteful number, since it uses less digits than its factorization.

31907878957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143084882.

The product of its (nonzero) digits is 26671680, while the sum is 64.

The spelling of 31907878957 in words is "thirty-one billion, nine hundred seven million, eight hundred seventy-eight thousand, nine hundred fifty-seven".