31531613513 has 4 divisors (see below), whose sum is σ = 32548762368. Its totient is φ = 30514464660.

The previous prime is 31531613489. The next prime is 31531613579.

31531613513 is nontrivially palindromic in base 10.

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 a de Polignac number, because none of the positive numbers 2^k-31531613513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31531613513.

It is not an unprimeable number, because it can be changed into a prime (31531613713) 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, 508574381 + ... + 508574442.

It is an arithmetic number, because the mean of its divisors is an integer number (8137190592).

Almost surely, 2^31531613513 is an apocalyptic number.

It is an amenable number.

31531613513 is a deficient number, since it is larger than the sum of its proper divisors (1017148855).

31531613513 is a wasteful number, since it uses less digits than its factorization.

31531613513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1017148854.

The product of its digits is 12150, while the sum is 32.

The spelling of 31531613513 in words is "thirty-one billion, five hundred thirty-one million, six hundred thirteen thousand, five hundred thirteen".