21311320200 has 96 divisors (see below), whose sum is σ = 66103581600. Its totient is φ = 5679708160.

The previous prime is 21311320181. The next prime is 21311320229. The reversal of 21311320200 is 202311312.

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 21311320200.

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, 1123999 + ... + 1142801.

It is an arithmetic number, because the mean of its divisors is an integer number (688578975).

Almost surely, 2^21311320200 is an apocalyptic number.

21311320200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311320200 is an abundant number, since it is smaller than the sum of its proper divisors (44792261400).

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

21311320200 is a wasteful number, since it uses less digits than its factorization.

21311320200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20711 (or 20702 counting only the distinct ones).

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

Adding to 21311320200 its reverse (202311312), we get a palindrome (21513631512).

The spelling of 21311320200 in words is "twenty-one billion, three hundred eleven million, three hundred twenty thousand, two hundred".