21123200100 has 72 divisors (see below), whose sum is σ = 62768288128. Its totient is φ = 5480611200.

The previous prime is 21123200099. The next prime is 21123200117. The reversal of 21123200100 is 100232112.

It is a Harshad number since it is a multiple of its sum of digits (12).

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, 940396 + ... + 962595.

Almost surely, 2^21123200100 is an apocalyptic number.

21123200100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21123200100 is an abundant number, since it is smaller than the sum of its proper divisors (41645088028).

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

21123200100 is a wasteful number, since it uses less digits than its factorization.

21123200100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1903045 (or 1903038 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21123200100 its reverse (100232112), we get a palindrome (21223432212).

The spelling of 21123200100 in words is "twenty-one billion, one hundred twenty-three million, two hundred thousand, one hundred".