21207918800 has 120 divisors (see below), whose sum is σ = 51899258592. Its totient is φ = 8326080000.

The previous prime is 21207918793. The next prime is 21207918811. The reversal of 21207918800 is 881970212.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

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, 20178275 + ... + 20179325.

Almost surely, 2^21207918800 is an apocalyptic number.

21207918800 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 21207918800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25949629296).

21207918800 is an abundant number, since it is smaller than the sum of its proper divisors (30691339792).

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

21207918800 is a wasteful number, since it uses less digits than its factorization.

21207918800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1957 (or 1946 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 21207918800 in words is "twenty-one billion, two hundred seven million, nine hundred eighteen thousand, eight hundred".