21753878400 has 960 divisors, whose sum is σ = 86774133600. Its totient is φ = 5352652800.

The previous prime is 21753878357. The next prime is 21753878401. The reversal of 21753878400 is 487835712.

21753878400 is a `hidden beast` number, since 2 + 1 + 7 + 538 + 78 + 40 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21753878401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 244425556 + ... + 244425644.

Almost surely, 2^21753878400 is an apocalyptic number.

21753878400 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 21753878400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43387066800).

21753878400 is an abundant number, since it is smaller than the sum of its proper divisors (65020255200).

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

21753878400 is a wasteful number, since it uses less digits than its factorization.

21753878400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 21753878400 in words is "twenty-one billion, seven hundred fifty-three million, eight hundred seventy-eight thousand, four hundred".