21312310020 has 48 divisors (see below), whose sum is σ = 60221958720. Its totient is φ = 5631140736.

The previous prime is 21312310003. The next prime is 21312310039. The reversal of 21312310020 is 2001321312.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1622842 + ... + 1635921.

It is an arithmetic number, because the mean of its divisors is an integer number (1254624140).

Almost surely, 2^21312310020 is an apocalyptic number.

21312310020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312310020 is an abundant number, since it is smaller than the sum of its proper divisors (38909648700).

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

21312310020 is a wasteful number, since it uses less digits than its factorization.

21312310020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3258884 (or 3258882 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21312310020 its reverse (2001321312), we get a palindrome (23313631332).

The spelling of 21312310020 in words is "twenty-one billion, three hundred twelve million, three hundred ten thousand, twenty".