21440764800 has 1344 divisors, whose sum is σ = 98705244960. Its totient is φ = 4478976000.

The previous prime is 21440764759. The next prime is 21440764819. The reversal of 21440764800 is 846704412.

21440764800 is a `hidden beast` number, since 2 + 1 + 4 + 4 + 0 + 7 + 648 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 212284750 + ... + 212284850.

Almost surely, 2^21440764800 is an apocalyptic number.

21440764800 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 21440764800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49352622480).

21440764800 is an abundant number, since it is smaller than the sum of its proper divisors (77264480160).

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

21440764800 is a wasteful number, since it uses less digits than its factorization.

21440764800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 21440764800 in words is "twenty-one billion, four hundred forty million, seven hundred sixty-four thousand, eight hundred".