21331320031 has 64 divisors (see below), whose sum is σ = 27141120000. Its totient is φ = 16368168960.

The previous prime is 21331320013. The next prime is 21331320047. The reversal of 21331320031 is 13002313312.

It is not a de Polignac number, because 21331320031 - 2⁹ = 21331319519 is a prime.

It is a super-2 number, since 2×21331320031² (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 = 21331319990 and 21331320008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331321031) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17078095 + ... + 17079343.

It is an arithmetic number, because the mean of its divisors is an integer number (424080000).

Almost surely, 2^21331320031 is an apocalyptic number.

21331320031 is a deficient number, since it is larger than the sum of its proper divisors (5809799969).

21331320031 is a wasteful number, since it uses less digits than its factorization.

21331320031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1424.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21331320031 its reverse (13002313312), we get a palindrome (34333633343).

The spelling of 21331320031 in words is "twenty-one billion, three hundred thirty-one million, three hundred twenty thousand, thirty-one".