31313513 has 16 divisors (see below), whose sum is σ = 39782016. Its totient is φ = 23936640.

The previous prime is 31313509. The next prime is 31313531. The reversal of 31313513 is 31531313.

It is not a de Polignac number, because 31313513 - 2² = 31313509 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31313563) 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, 245 + ... + 7917.

It is an arithmetic number, because the mean of its divisors is an integer number (2486376).

Almost surely, 2^31313513 is an apocalyptic number.

It is an amenable number.

31313513 is a deficient number, since it is larger than the sum of its proper divisors (8468503).

31313513 is a wasteful number, since it uses less digits than its factorization.

31313513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7744.

The product of its digits is 405, while the sum is 20.

The square root of 31313513 is about 5595.8478356724. The cubic root of 31313513 is about 315.1935083791.

Adding to 31313513 its reverse (31531313), we get a palindrome (62844826).

The spelling of 31313513 in words is "thirty-one million, three hundred thirteen thousand, five hundred thirteen".