21031313321 has 16 divisors (see below), whose sum is σ = 22167575424. Its totient is φ = 19913988864.

The previous prime is 21031313279. The next prime is 21031313339. The reversal of 21031313321 is 12331313012.

It is a cyclic number.

It is not a de Polignac number, because 21031313321 - 2³⁴ = 3851444137 is a prime.

It is a super-2 number, since 2×21031313321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031313293 and 21031313302.

It is not an unprimeable number, because it can be changed into a prime (21031316321) 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, 2274710 + ... + 2283936.

It is an arithmetic number, because the mean of its divisors is an integer number (1385473464).

Almost surely, 2^21031313321 is an apocalyptic number.

It is an amenable number.

21031313321 is a deficient number, since it is larger than the sum of its proper divisors (1136262103).

21031313321 is a wasteful number, since it uses less digits than its factorization.

21031313321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10240.

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

Adding to 21031313321 its reverse (12331313012), we get a palindrome (33362626333).

The spelling of 21031313321 in words is "twenty-one billion, thirty-one million, three hundred thirteen thousand, three hundred twenty-one".