21011220102100 has 36 divisors (see below), whose sum is σ = 45594549762048. Its totient is φ = 8404450780000.

The previous prime is 21011220102083. The next prime is 21011220102107. The reversal of 21011220102100 is 120102211012.

It is a super-2 number, since 2×21011220102100² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011220102107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38042925 + ... + 38591275.

It is an arithmetic number, because the mean of its divisors is an integer number (1266515271168).

Almost surely, 2^{21011220102100} is an apocalyptic number.

21011220102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011220102100 is an abundant number, since it is smaller than the sum of its proper divisors (24583329659948).

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

21011220102100 is a wasteful number, since it uses less digits than its factorization.

21011220102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 931536 (or 931529 counting only the distinct ones).

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

Adding to 21011220102100 its reverse (120102211012), we get a palindrome (21131322313112).

The spelling of 21011220102100 in words is "twenty-one trillion, eleven billion, two hundred twenty million, one hundred two thousand, one hundred".