31375681 has 12 divisors (see below), whose sum is σ = 32711040. Its totient is φ = 30087960.

The previous prime is 31375661. The next prime is 31375697. The reversal of 31375681 is 18657313.

It is not a de Polignac number, because 31375681 - 2¹³ = 31367489 is a prime.

It is a super-2 number, since 2×31375681² = 1968866716427522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31375601) 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, 131160 + ... + 131398.

It is an arithmetic number, because the mean of its divisors is an integer number (2725920).

Almost surely, 2^31375681 is an apocalyptic number.

It is an amenable number.

31375681 is a deficient number, since it is larger than the sum of its proper divisors (1335359).

31375681 is an equidigital number, since it uses as much as digits as its factorization.

31375681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396 (or 353 counting only the distinct ones).

The product of its digits is 15120, while the sum is 34.

The square root of 31375681 is about 5601.3999143071. The cubic root of 31375681 is about 315.4019593522.

The spelling of 31375681 in words is "thirty-one million, three hundred seventy-five thousand, six hundred eighty-one".