21012332100 has 72 divisors (see below), whose sum is σ = 61048155168. Its totient is φ = 5580019200.

The previous prime is 21012332071. The next prime is 21012332147. The reversal of 21012332100 is 123321012.

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 21012332100.

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, 73014 + ... + 217613.

It is an arithmetic number, because the mean of its divisors is an integer number (847891044).

Almost surely, 2^21012332100 is an apocalyptic number.

21012332100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012332100 is an abundant number, since it is smaller than the sum of its proper divisors (40035823068).

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

21012332100 is a wasteful number, since it uses less digits than its factorization.

21012332100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290885 (or 290878 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21012332100 its reverse (123321012), we get a palindrome (21135653112).

The spelling of 21012332100 in words is "twenty-one billion, twelve million, three hundred thirty-two thousand, one hundred".