31386957561 has 12 divisors (see below), whose sum is σ = 45339158592. Its totient is φ = 20923511256.

The previous prime is 31386957517. The next prime is 31386957571. The reversal of 31386957561 is 16575968313.

31386957561 is a `hidden beast` number, since 3 + 1 + 3 + 8 + 6 + 9 + 575 + 61 = 666.

It is not a de Polignac number, because 31386957561 - 2¹⁴ = 31386941177 is a prime.

It is a super-2 number, since 2×31386957561² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31386957498 and 31386957507.

It is not an unprimeable number, because it can be changed into a prime (31386957571) 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, 104500 + ... + 271466.

It is an arithmetic number, because the mean of its divisors is an integer number (3778263216).

Almost surely, 2^31386957561 is an apocalyptic number.

It is an amenable number.

31386957561 is a deficient number, since it is larger than the sum of its proper divisors (13952201031).

31386957561 is a wasteful number, since it uses less digits than its factorization.

31386957561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187860 (or 187857 counting only the distinct ones).

The product of its digits is 4082400, while the sum is 54.

The spelling of 31386957561 in words is "thirty-one billion, three hundred eighty-six million, nine hundred fifty-seven thousand, five hundred sixty-one".