31113513 has 12 divisors (see below), whose sum is σ = 44992948. Its totient is φ = 20718720.

The previous prime is 31113497. The next prime is 31113521. The reversal of 31113513 is 31531113.

31113513 is a `hidden beast` number, since 311 + 1 + 351 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 29680704 + 1432809 = 5448^2 + 1197^2 .

It is not a de Polignac number, because 31113513 - 2⁴ = 31113497 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31113113) 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, 10581 + ... + 13197.

Almost surely, 2^31113513 is an apocalyptic number.

It is an amenable number.

31113513 is a deficient number, since it is larger than the sum of its proper divisors (13879435).

31113513 is a wasteful number, since it uses less digits than its factorization.

31113513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944 (or 3941 counting only the distinct ones).

The product of its digits is 135, while the sum is 18.

The square root of 31113513 is about 5577.9488165454. The cubic root of 31113513 is about 314.5210256534.

Adding to 31113513 its reverse (31531113), we get a palindrome (62644626).

It can be divided in two parts, 31113 and 513, that added together give a triangular number (31626 = T₂₅₁).

The spelling of 31113513 in words is "thirty-one million, one hundred thirteen thousand, five hundred thirteen".