21031232320 has 56 divisors (see below), whose sum is σ = 57235002624. Its totient is φ = 7210707456.

The previous prime is 21031232293. The next prime is 21031232347. The reversal of 21031232320 is 2323213012.

It is an interprime number because it is at equal distance from previous prime (21031232293) and next prime (21031232347).

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4692232 + ... + 4696711.

Almost surely, 2^21031232320 is an apocalyptic number.

21031232320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031232320 is an abundant number, since it is smaller than the sum of its proper divisors (36203770304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031232320 is an equidigital number, since it uses as much as digits as its factorization.

21031232320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9388967 (or 9388957 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21031232320 its reverse (2323213012), we get a palindrome (23354445332).

The spelling of 21031232320 in words is "twenty-one billion, thirty-one million, two hundred thirty-two thousand, three hundred twenty".