21864268800 has 396 divisors, whose sum is σ = 85411091376. Its totient is φ = 5299814400.

The previous prime is 21864268799. The next prime is 21864268817. The reversal of 21864268800 is 886246812.

21864268800 is a `hidden beast` number, since 218 + 6 + 426 + 8 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (396).

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2530087 + ... + 2538713.

Almost surely, 2^21864268800 is an apocalyptic number.

21864268800 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 21864268800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42705545688).

21864268800 is an abundant number, since it is smaller than the sum of its proper divisors (63546822576).

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

21864268800 is a wasteful number, since it uses less digits than its factorization.

21864268800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8674 (or 8648 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The spelling of 21864268800 in words is "twenty-one billion, eight hundred sixty-four million, two hundred sixty-eight thousand, eight hundred".