21200111100 has 144 divisors (see below), whose sum is σ = 77890848000. Its totient is φ = 4845735360.

The previous prime is 21200111089. The next prime is 21200111131. The reversal of 21200111100 is 111100212.

It is a happy number.

It is a super-3 number, since 3×21200111100³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 541950 + ... + 579749.

Almost surely, 2^21200111100 is an apocalyptic number.

21200111100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200111100 is an abundant number, since it is smaller than the sum of its proper divisors (56690736900).

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

21200111100 is a wasteful number, since it uses less digits than its factorization.

21200111100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121729 (or 1121716 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21200111100 its reverse (111100212), we get a palindrome (21311211312).

The spelling of 21200111100 in words is "twenty-one billion, two hundred million, one hundred eleven thousand, one hundred".