21001122112100 has 72 divisors (see below), whose sum is σ = 49563928075368. Its totient is φ = 7677485568000.

The previous prime is 21001122112039. The next prime is 21001122112133. The reversal of 21001122112100 is 121122110012.

It can be written as a sum of positive squares in 12 ways, for example, as 1727757771364 + 19273364340736 = 1314442^2 + 4390144^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79842509 + ... + 80105108.

Almost surely, 2^{21001122112100} is an apocalyptic number.

21001122112100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001122112100 is an abundant number, since it is smaller than the sum of its proper divisors (28562805963268).

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

21001122112100 is a wasteful number, since it uses less digits than its factorization.

21001122112100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159947745 (or 159947738 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21001122112100 its reverse (121122110012), we get a palindrome (21122244222112).

The spelling of 21001122112100 in words is "twenty-one trillion, one billion, one hundred twenty-two million, one hundred twelve thousand, one hundred".