31520013313 has 4 divisors (see below), whose sum is σ = 32536787968. Its totient is φ = 30503238660.

The previous prime is 31520013299. The next prime is 31520013331. The reversal of 31520013313 is 31331002513.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31520013313 - 2⁹ = 31520012801 is a prime.

It is a super-2 number, since 2×31520013313² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31520013353) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 508387281 + ... + 508387342.

It is an arithmetic number, because the mean of its divisors is an integer number (8134196992).

Almost surely, 2^31520013313 is an apocalyptic number.

It is an amenable number.

31520013313 is a deficient number, since it is larger than the sum of its proper divisors (1016774655).

31520013313 is a wasteful number, since it uses less digits than its factorization.

31520013313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016774654.

The product of its (nonzero) digits is 810, while the sum is 22.

Adding to 31520013313 its reverse (31331002513), we get a palindrome (62851015826).

The spelling of 31520013313 in words is "thirty-one billion, five hundred twenty million, thirteen thousand, three hundred thirteen".