21220022220 has 48 divisors (see below), whose sum is σ = 59575417440. Its totient is φ = 5643495936.

The previous prime is 21220022209. The next prime is 21220022231. The reversal of 21220022220 is 2222002212.

It is an interprime number because it is at equal distance from previous prime (21220022209) and next prime (21220022231).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21220022220.

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, 451705 + ... + 496464.

It is an arithmetic number, because the mean of its divisors is an integer number (1241154530).

Almost surely, 2^21220022220 is an apocalyptic number.

21220022220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220022220 is an abundant number, since it is smaller than the sum of its proper divisors (38355395220).

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

21220022220 is a wasteful number, since it uses less digits than its factorization.

21220022220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948554 (or 948552 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

Adding to 21220022220 its reverse (2222002212), we get a palindrome (23442024432).

The spelling of 21220022220 in words is "twenty-one billion, two hundred twenty million, twenty-two thousand, two hundred twenty".