21243931200 has 504 divisors, whose sum is σ = 77764001952. Its totient is φ = 5498634240.

The previous prime is 21243931171. The next prime is 21243931243. The reversal of 21243931200 is 213934212.

It is a happy number.

21243931200 is a `hidden beast` number, since 21 + 2 + 439 + 3 + 1 + 200 = 666.

It is a super-2 number, since 2×21243931200² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 93585487 + ... + 93585713.

Almost surely, 2^21243931200 is an apocalyptic number.

21243931200 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 21243931200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38882000976).

21243931200 is an abundant number, since it is smaller than the sum of its proper divisors (56520070752).

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

21243931200 is a wasteful number, since it uses less digits than its factorization.

21243931200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The spelling of 21243931200 in words is "twenty-one billion, two hundred forty-three million, nine hundred thirty-one thousand, two hundred".