21100122100120 has 64 divisors (see below), whose sum is σ = 54816812124480. Its totient is φ = 7159746871296.

The previous prime is 21100122100111. The next prime is 21100122100139. The reversal of 21100122100120 is 2100122100112.

It is a self number, because there is not a number n which added to its sum of digits gives 21100122100120.

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, 388413969 + ... + 388468288.

It is an arithmetic number, because the mean of its divisors is an integer number (856512689445).

Almost surely, 2^{21100122100120} is an apocalyptic number.

21100122100120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100122100120 is an abundant number, since it is smaller than the sum of its proper divisors (33716690024360).

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

21100122100120 is a wasteful number, since it uses less digits than its factorization.

21100122100120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776882372 (or 776882368 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21100122100120 its reverse (2100122100112), we get a palindrome (23200244200232).

The spelling of 21100122100120 in words is "twenty-one trillion, one hundred billion, one hundred twenty-two million, one hundred thousand, one hundred twenty".