21643876800 has 1008 divisors, whose sum is σ = 96302169600. Its totient is φ = 4488929280.

The previous prime is 21643876789. The next prime is 21643876879. The reversal of 21643876800 is 867834612.

It is a tau number, because it is divible by the number of its divisors (1008).

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

It is a congruent number.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 108763101 + ... + 108763299.

Almost surely, 2^21643876800 is an apocalyptic number.

21643876800 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 21643876800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48151084800).

21643876800 is an abundant number, since it is smaller than the sum of its proper divisors (74658292800).

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

21643876800 is a wasteful number, since it uses less digits than its factorization.

21643876800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 21643876800 in words is "twenty-one billion, six hundred forty-three million, eight hundred seventy-six thousand, eight hundred".