21021033020020 has 72 divisors (see below), whose sum is σ = 48523148023392. Its totient is φ = 7643847456960.

The previous prime is 21021033020017. The next prime is 21021033020051. The reversal of 21021033020020 is 2002033012012.

It is a junction number, because it is equal to n+sod(n) for n = 21021033019976 and 21021033020003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 208270407 + ... + 208371313.

It is an arithmetic number, because the mean of its divisors is an integer number (673932611436).

Almost surely, 2^{21021033020020} is an apocalyptic number.

21021033020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021033020020 is an abundant number, since it is smaller than the sum of its proper divisors (27502115003372).

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

21021033020020 is a wasteful number, since it uses less digits than its factorization.

21021033020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187021 (or 187008 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21021033020020 its reverse (2002033012012), we get a palindrome (23023066032032).

The spelling of 21021033020020 in words is "twenty-one trillion, twenty-one billion, thirty-three million, twenty thousand, twenty".