31878755657 has 12 divisors (see below), whose sum is σ = 38702040960. Its totient is φ = 25717313856.

The previous prime is 31878755651. The next prime is 31878755663. The reversal of 31878755657 is 75655787813.

It is an interprime number because it is at equal distance from previous prime (31878755651) and next prime (31878755663).

It is not a de Polignac number, because 31878755657 - 2⁸ = 31878755401 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31878755657.

It is not an unprimeable number, because it can be changed into a prime (31878755651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7877057 + ... + 7881102.

It is an arithmetic number, because the mean of its divisors is an integer number (3225170080).

Almost surely, 2^31878755657 is an apocalyptic number.

It is an amenable number.

31878755657 is a deficient number, since it is larger than the sum of its proper divisors (6823285303).

31878755657 is a wasteful number, since it uses less digits than its factorization.

31878755657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15758200 (or 15758183 counting only the distinct ones).

The product of its digits is 49392000, while the sum is 62.

The spelling of 31878755657 in words is "thirty-one billion, eight hundred seventy-eight million, seven hundred fifty-five thousand, six hundred fifty-seven".