21222100020 has 48 divisors (see below), whose sum is σ = 64823871168. Its totient is φ = 5144751360.

The previous prime is 21222099973. The next prime is 21222100087. The reversal of 21222100020 is 2000122212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21222099969 and 21222100005.

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, 16076689 + ... + 16078008.

It is an arithmetic number, because the mean of its divisors is an integer number (1350497316).

Almost surely, 2^21222100020 is an apocalyptic number.

21222100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222100020 is an abundant number, since it is smaller than the sum of its proper divisors (43601771148).

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

21222100020 is a wasteful number, since it uses less digits than its factorization.

21222100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32154720 (or 32154718 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21222100020 its reverse (2000122212), we get a palindrome (23222222232).

The spelling of 21222100020 in words is "twenty-one billion, two hundred twenty-two million, one hundred thousand, twenty".