21200220020 has 48 divisors (see below), whose sum is σ = 51102791040. Its totient is φ = 7236895104.

The previous prime is 21200219987. The next prime is 21200220049. The reversal of 21200220020 is 2002200212.

It is a junction number, because it is equal to n+sod(n) for n = 21200219983 and 21200220010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 298574 + ... + 362693.

It is an arithmetic number, because the mean of its divisors is an integer number (1064641480).

Almost surely, 2^21200220020 is an apocalyptic number.

21200220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200220020 is an abundant number, since it is smaller than the sum of its proper divisors (29902571020).

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

21200220020 is a wasteful number, since it uses less digits than its factorization.

21200220020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661512 (or 661510 counting only the distinct ones).

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

Adding to 21200220020 its reverse (2002200212), we get a palindrome (23202420232).

The spelling of 21200220020 in words is "twenty-one billion, two hundred million, two hundred twenty thousand, twenty".