21100220102100 has 72 divisors (see below), whose sum is σ = 61063140021408. Its totient is φ = 5625511548800.

The previous prime is 21100220101997. The next prime is 21100220102111. The reversal of 21100220102100 is 120102200112.

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

It is a congruent number.

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, 6192906 + ... + 8975105.

It is an arithmetic number, because the mean of its divisors is an integer number (848099166964).

Almost surely, 2^{21100220102100} is an apocalyptic number.

21100220102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100220102100 is an abundant number, since it is smaller than the sum of its proper divisors (39962919919308).

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

21100220102100 is a wasteful number, since it uses less digits than its factorization.

21100220102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15172665 (or 15172658 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21100220102100 its reverse (120102200112), we get a palindrome (21220322302212).

The spelling of 21100220102100 in words is "twenty-one trillion, one hundred billion, two hundred twenty million, one hundred two thousand, one hundred".