21864001525920 has 288 divisors, whose sum is σ = 76673694883968. Its totient is φ = 5669395974144.

The previous prime is 21864001525909. The next prime is 21864001525969. The reversal of 21864001525920 is 2952510046812.

21864001525920 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 4 + 0 + 0 + 1 + 52 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88694677 + ... + 88940843.

It is an arithmetic number, because the mean of its divisors is an integer number (266228107236).

Almost surely, 2^{21864001525920} is an apocalyptic number.

21864001525920 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 21864001525920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38336847441984).

21864001525920 is an abundant number, since it is smaller than the sum of its proper divisors (54809693358048).

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

21864001525920 is a wasteful number, since it uses less digits than its factorization.

21864001525920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247892 (or 247881 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 21864001525920 in words is "twenty-one trillion, eight hundred sixty-four billion, one million, five hundred twenty-five thousand, nine hundred twenty".