31331023013 has 4 divisors (see below), whose sum is σ = 32095194348. Its totient is φ = 30566851680.

The previous prime is 31331022997. The next prime is 31331023033. The reversal of 31331023013 is 31032013313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3149678884 + 28181344129 = 56122^2 + 167873^2 .

It is a cyclic number.

It is not a de Polignac number, because 31331023013 - 2⁴ = 31331022997 is a prime.

It is a super-2 number, since 2×31331023013² (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 (31331023033) 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, 382085606 + ... + 382085687.

It is an arithmetic number, because the mean of its divisors is an integer number (8023798587).

Almost surely, 2^31331023013 is an apocalyptic number.

It is an amenable number.

31331023013 is a deficient number, since it is larger than the sum of its proper divisors (764171335).

31331023013 is an equidigital number, since it uses as much as digits as its factorization.

31331023013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764171334.

The product of its (nonzero) digits is 486, while the sum is 20.

Adding to 31331023013 its reverse (31032013313), we get a palindrome (62363036326).

The spelling of 31331023013 in words is "thirty-one billion, three hundred thirty-one million, twenty-three thousand, thirteen".