21020202220 has 24 divisors (see below), whose sum is σ = 44155317024. Its totient is φ = 8405625216.

The previous prime is 21020202179. The next prime is 21020202233. The reversal of 21020202220 is 2220202012.

It is a self number, because there is not a number n which added to its sum of digits gives 21020202220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82489 + ... + 221008.

It is an arithmetic number, because the mean of its divisors is an integer number (1839804876).

Almost surely, 2^21020202220 is an apocalyptic number.

21020202220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020202220 is an abundant number, since it is smaller than the sum of its proper divisors (23135114804).

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

21020202220 is a wasteful number, since it uses less digits than its factorization.

21020202220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306969 (or 306967 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 21020202220 its reverse (2220202012), we get a palindrome (23240404232).

The spelling of 21020202220 in words is "twenty-one billion, twenty million, two hundred two thousand, two hundred twenty".