21331021331 has 16 divisors (see below), whose sum is σ = 21888806688. Its totient is φ = 20782080000.

The previous prime is 21331021321. The next prime is 21331021357. The reversal of 21331021331 is 13312013312.

It is a cyclic number.

It is not a de Polignac number, because 21331021331 - 2³⁴ = 4151152147 is a prime.

It is a super-2 number, since 2×21331021331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21331021321) 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, 2149481 + ... + 2159381.

It is an arithmetic number, because the mean of its divisors is an integer number (1368050418).

Almost surely, 2^21331021331 is an apocalyptic number.

21331021331 is a deficient number, since it is larger than the sum of its proper divisors (557785357).

21331021331 is a wasteful number, since it uses less digits than its factorization.

21331021331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10342.

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

Adding to 21331021331 its reverse (13312013312), we get a palindrome (34643034643).

The spelling of 21331021331 in words is "twenty-one billion, three hundred thirty-one million, twenty-one thousand, three hundred thirty-one".