31318681 has 16 divisors (see below), whose sum is σ = 33053440. Its totient is φ = 29652480.

The previous prime is 31318621. The next prime is 31318691. The reversal of 31318681 is 18681313.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31318681 is a prime.

It is a super-2 number, since 2×31318681² = 1961719559159522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31318621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 322825 + ... + 322921.

It is an arithmetic number, because the mean of its divisors is an integer number (2065840).

Almost surely, 2^31318681 is an apocalyptic number.

It is an amenable number.

31318681 is a deficient number, since it is larger than the sum of its proper divisors (1734759).

31318681 is an equidigital number, since it uses as much as digits as its factorization.

31318681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304.

The product of its digits is 3456, while the sum is 31.

The square root of 31318681 is about 5596.3095875764. The cubic root of 31318681 is about 315.2108473306.

Adding to 31318681 its reverse (18681313), we get a palindrome (49999994).

The spelling of 31318681 in words is "thirty-one million, three hundred eighteen thousand, six hundred eighty-one".