31287663081 has 24 divisors (see below), whose sum is σ = 45859806720. Its totient is φ = 20551204800.

The previous prime is 31287663059. The next prime is 31287663083. The reversal of 31287663081 is 18036678213.

31287663081 is a `hidden beast` number, since 3 + 1 + 2 + 8 + 7 + 6 + 630 + 8 + 1 = 666.

It is not a de Polignac number, because 31287663081 - 2⁷ = 31287662953 is a prime.

It is a super-2 number, since 2×31287663081² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31287663083) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1012936 + ... + 1043366.

It is an arithmetic number, because the mean of its divisors is an integer number (1910825280).

Almost surely, 2^31287663081 is an apocalyptic number.

It is an amenable number.

31287663081 is a deficient number, since it is larger than the sum of its proper divisors (14572143639).

31287663081 is a wasteful number, since it uses less digits than its factorization.

31287663081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32117 (or 32114 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 31287663081 in words is "thirty-one billion, two hundred eighty-seven million, six hundred sixty-three thousand, eighty-one".