31231312013 has 24 divisors (see below), whose sum is σ = 35730719136. Its totient is φ = 27070392800.

The previous prime is 31231312009. The next prime is 31231312039. The reversal of 31231312013 is 31021313213.

It is not a de Polignac number, because 31231312013 - 2² = 31231312009 is a prime.

It is a super-2 number, since 2×31231312013² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231312003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1836158 + ... + 1853088.

It is an arithmetic number, because the mean of its divisors is an integer number (1488779964).

Almost surely, 2^31231312013 is an apocalyptic number.

It is an amenable number.

31231312013 is a deficient number, since it is larger than the sum of its proper divisors (4499407123).

31231312013 is a wasteful number, since it uses less digits than its factorization.

31231312013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17305 (or 17282 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31231312013 its reverse (31021313213), we get a palindrome (62252625226).

The spelling of 31231312013 in words is "thirty-one billion, two hundred thirty-one million, three hundred twelve thousand, thirteen".