21202020020 has 24 divisors (see below), whose sum is σ = 45188785824. Its totient is φ = 8354228256.

The previous prime is 21202020013. The next prime is 21202020041. The reversal of 21202020020 is 2002020212.

It is a junction number, because it is equal to n+sod(n) for n = 21202019983 and 21202020010.

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, 7909862 + ... + 7912541.

It is an arithmetic number, because the mean of its divisors is an integer number (1882866076).

Almost surely, 2^21202020020 is an apocalyptic number.

21202020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202020020 is an abundant number, since it is smaller than the sum of its proper divisors (23986765804).

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

21202020020 is a wasteful number, since it uses less digits than its factorization.

21202020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15822479 (or 15822477 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

Adding to 21202020020 its reverse (2002020212), we get a palindrome (23204040232).

The spelling of 21202020020 in words is "twenty-one billion, two hundred two million, twenty thousand, twenty".