21112121222100 has 108 divisors (see below), whose sum is σ = 66817244874016. Its totient is φ = 5575239754560.

The previous prime is 21112121222063. The next prime is 21112121222147. The reversal of 21112121222100 is 122212121112.

21112121222100 is a `hidden beast` number, since 211 + 1 + 21 + 212 + 221 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 113780662 + ... + 113966061.

Almost surely, 2^{21112121222100} is an apocalyptic number.

21112121222100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112121222100 is an abundant number, since it is smaller than the sum of its proper divisors (45705123651916).

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

21112121222100 is a wasteful number, since it uses less digits than its factorization.

21112121222100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227746846 (or 227746836 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21112121222100 its reverse (122212121112), we get a palindrome (21234333343212).

The spelling of 21112121222100 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred".