21121111112100 has 72 divisors (see below), whose sum is σ = 61143078342528. Its totient is φ = 5629285833600.

The previous prime is 21121111112051. The next prime is 21121111112191. The reversal of 21121111112100 is 121111112112.

It is a super-2 number, since 2×21121111112100² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21121111112100.

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, 18253159 + ... + 19375758.

It is an arithmetic number, because the mean of its divisors is an integer number (849209421424).

Almost surely, 2^{21121111112100} is an apocalyptic number.

21121111112100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121111112100 is an abundant number, since it is smaller than the sum of its proper divisors (40021967230428).

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

21121111112100 is a wasteful number, since it uses less digits than its factorization.

21121111112100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37630805 (or 37630798 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 21121111112100 its reverse (121111112112), we get a palindrome (21242222224212).

The spelling of 21121111112100 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, one hundred twelve thousand, one hundred".