21012320120 has 32 divisors (see below), whose sum is σ = 51575695920. Its totient is φ = 7640843520.

The previous prime is 21012320117. The next prime is 21012320143. The reversal of 21012320120 is 2102321012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21012320095 and 21012320104.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23877197 + ... + 23878076.

Almost surely, 2^21012320120 is an apocalyptic number.

21012320120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012320120 is an abundant number, since it is smaller than the sum of its proper divisors (30563375800).

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

21012320120 is a wasteful number, since it uses less digits than its factorization.

21012320120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47755295 (or 47755291 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21012320120 its reverse (2102321012), we get a palindrome (23114641132).

The spelling of 21012320120 in words is "twenty-one billion, twelve million, three hundred twenty thousand, one hundred twenty".