21031312123200 has 672 divisors, whose sum is σ = 70710162831360. Its totient is φ = 5471391744000.

The previous prime is 21031312123153. The next prime is 21031312123273. The reversal of 21031312123200 is 232121313012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20010762675 + ... + 20010763725.

Almost surely, 2^{21031312123200} is an apocalyptic number.

21031312123200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21031312123200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35355081415680).

21031312123200 is an abundant number, since it is smaller than the sum of its proper divisors (49678850708160).

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

21031312123200 is a wasteful number, since it uses less digits than its factorization.

21031312123200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1735 (or 1720 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21031312123200 its reverse (232121313012), we get a palindrome (21263433436212).

The spelling of 21031312123200 in words is "twenty-one trillion, thirty-one billion, three hundred twelve million, one hundred twenty-three thousand, two hundred".