21200022020 has 12 divisors (see below), whose sum is σ = 44520046284. Its totient is φ = 8480008800.

The previous prime is 21200022017. The next prime is 21200022031. The reversal of 21200022020 is 2022000212.

It can be written as a sum of positive squares in 2 ways, for example, as 15339813316 + 5860208704 = 123854^2 + 76552^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21200021992 and 21200022010.

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, 530000531 + ... + 530000570.

It is an arithmetic number, because the mean of its divisors is an integer number (3710003857).

Almost surely, 2^21200022020 is an apocalyptic number.

21200022020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200022020 is an abundant number, since it is smaller than the sum of its proper divisors (23320024264).

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

21200022020 is a wasteful number, since it uses less digits than its factorization.

21200022020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060001110 (or 1060001108 counting only the distinct ones).

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

Adding to 21200022020 its reverse (2022000212), we get a palindrome (23222022232).

The spelling of 21200022020 in words is "twenty-one billion, two hundred million, twenty-two thousand, twenty".