21102000221220 has 48 divisors (see below), whose sum is σ = 62561224188288. Its totient is φ = 5296188290560.

The previous prime is 21102000221219. The next prime is 21102000221221. The reversal of 21102000221220 is 2212200020112.

It is an interprime number because it is at equal distance from previous prime (21102000221219) and next prime (21102000221221).

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 21102000221220.

It is not an unprimeable number, because it can be changed into a prime (21102000221221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10344116736 + ... + 10344118775.

It is an arithmetic number, because the mean of its divisors is an integer number (1303358837256).

Almost surely, 2^{21102000221220} is an apocalyptic number.

21102000221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102000221220 is an abundant number, since it is smaller than the sum of its proper divisors (41459223967068).

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

21102000221220 is a wasteful number, since it uses less digits than its factorization.

21102000221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20688235540 (or 20688235538 counting only the distinct ones).

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

Adding to 21102000221220 its reverse (2212200020112), we get a palindrome (23314200241332).

The spelling of 21102000221220 in words is "twenty-one trillion, one hundred two billion, two hundred twenty-one thousand, two hundred twenty".