21021220111100 has 36 divisors (see below), whose sum is σ = 49762961065608. Its totient is φ = 7644080040000.

The previous prime is 21021220111063. The next prime is 21021220111103. The reversal of 21021220111100 is 111102212012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021220111103) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 9555098951 + ... + 9555101150.

Almost surely, 2^{21021220111100} is an apocalyptic number.

21021220111100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021220111100 is an abundant number, since it is smaller than the sum of its proper divisors (28741740954508).

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

21021220111100 is a wasteful number, since it uses less digits than its factorization.

21021220111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19110200126 (or 19110200119 counting only the distinct ones).

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

Adding to 21021220111100 its reverse (111102212012), we get a palindrome (21132322323112).

The spelling of 21021220111100 in words is "twenty-one trillion, twenty-one billion, two hundred twenty million, one hundred eleven thousand, one hundred".