21310031313 has 16 divisors (see below), whose sum is σ = 31619237760. Its totient is φ = 14184718128.

The previous prime is 21310031293. The next prime is 21310031321. The reversal of 21310031313 is 31313001312.

It is a happy number.

It is not a de Polignac number, because 21310031313 - 2²⁴ = 21293254097 is a prime.

It is a super-2 number, since 2×21310031313² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21310031333) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 592470 + ... + 627407.

It is an arithmetic number, because the mean of its divisors is an integer number (1976202360).

Almost surely, 2^21310031313 is an apocalyptic number.

It is an amenable number.

21310031313 is a deficient number, since it is larger than the sum of its proper divisors (10309206447).

21310031313 is a wasteful number, since it uses less digits than its factorization.

21310031313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1220533 (or 1220527 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

Adding to 21310031313 its reverse (31313001312), we get a palindrome (52623032625).

The spelling of 21310031313 in words is "twenty-one billion, three hundred ten million, thirty-one thousand, three hundred thirteen".