31956465881 has 2 divisors, whose sum is σ = 31956465882. Its totient is φ = 31956465880.

The previous prime is 31956465841. The next prime is 31956465923. The reversal of 31956465881 is 18856465913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27785889481 + 4170576400 = 166691^2 + 64580^2 .

It is an emirp because it is prime and its reverse (18856465913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31956465881 - 2³⁴ = 14776596697 is a prime.

It is a super-3 number, since 3×31956465881³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31956465841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15978232940 + 15978232941.

It is an arithmetic number, because the mean of its divisors is an integer number (15978232941).

Almost surely, 2^31956465881 is an apocalyptic number.

It is an amenable number.

31956465881 is a deficient number, since it is larger than the sum of its proper divisors (1).

31956465881 is an equidigital number, since it uses as much as digits as its factorization.

31956465881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6220800, while the sum is 56.

The spelling of 31956465881 in words is "thirty-one billion, nine hundred fifty-six million, four hundred sixty-five thousand, eight hundred eighty-one".