21031221013200 has 120 divisors (see below), whose sum is σ = 74855568163200. Its totient is φ = 5608325600640.

The previous prime is 21031221013193. The next prime is 21031221013219. The reversal of 21031221013200 is 231012213012.

21031221013200 is a `hidden beast` number, since 2 + 10 + 312 + 21 + 0 + 1 + 320 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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, 973656840 + ... + 973678439.

It is an arithmetic number, because the mean of its divisors is an integer number (623796401360).

Almost surely, 2^{21031221013200} is an apocalyptic number.

21031221013200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031221013200 is an abundant number, since it is smaller than the sum of its proper divisors (53824347150000).

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

21031221013200 is a wasteful number, since it uses less digits than its factorization.

21031221013200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1947335306 (or 1947335289 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21031221013200 its reverse (231012213012), we get a palindrome (21262233226212).

The spelling of 21031221013200 in words is "twenty-one trillion, thirty-one billion, two hundred twenty-one million, thirteen thousand, two hundred".