21012002121020 has 12 divisors (see below), whose sum is σ = 44125204454184. Its totient is φ = 8404800848400.

The previous prime is 21012002121017. The next prime is 21012002121041. The reversal of 21012002121020 is 2012120021012.

It is a junction number, because it is equal to n+sod(n) for n = 21012002120986 and 21012002121004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525300053006 + ... + 525300053045.

It is an arithmetic number, because the mean of its divisors is an integer number (3677100371182).

Almost surely, 2^{21012002121020} is an apocalyptic number.

21012002121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012002121020 is an abundant number, since it is smaller than the sum of its proper divisors (23113202333164).

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

21012002121020 is a wasteful number, since it uses less digits than its factorization.

21012002121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050600106060 (or 1050600106058 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21012002121020 its reverse (2012120021012), we get a palindrome (23024122142032).

The spelling of 21012002121020 in words is "twenty-one trillion, twelve billion, two million, one hundred twenty-one thousand, twenty".