21221022120 has 64 divisors (see below), whose sum is σ = 63681880320. Its totient is φ = 5657266944.

The previous prime is 21221022113. The next prime is 21221022167. The reversal of 21221022120 is 2122012212.

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 21221022120.

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, 412129 + ... + 460751.

It is an arithmetic number, because the mean of its divisors is an integer number (995029380).

Almost surely, 2^21221022120 is an apocalyptic number.

21221022120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221022120 is an abundant number, since it is smaller than the sum of its proper divisors (42460858200).

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

21221022120 is a wasteful number, since it uses less digits than its factorization.

21221022120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52274 (or 52270 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21221022120 its reverse (2122012212), we get a palindrome (23343034332).

The spelling of 21221022120 in words is "twenty-one billion, two hundred twenty-one million, twenty-two thousand, one hundred twenty".