21231031200 has 72 divisors (see below), whose sum is σ = 69107014368. Its totient is φ = 5661607680.

The previous prime is 21231031193. The next prime is 21231031223. The reversal of 21231031200 is 213013212.

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 21231031200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4420732 + ... + 4425531.

It is an arithmetic number, because the mean of its divisors is an integer number (959819644).

Almost surely, 2^21231031200 is an apocalyptic number.

21231031200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231031200 is an abundant number, since it is smaller than the sum of its proper divisors (47875983168).

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

21231031200 is a wasteful number, since it uses less digits than its factorization.

21231031200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8846286 (or 8846273 counting only the distinct ones).

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

Adding to 21231031200 its reverse (213013212), we get a palindrome (21444044412).

The spelling of 21231031200 in words is "twenty-one billion, two hundred thirty-one million, thirty-one thousand, two hundred".