21840256972800 has 1152 divisors, whose sum is σ = 97077461644800. Its totient is φ = 4698372833280.

The previous prime is 21840256972769. The next prime is 21840256972883. The reversal of 21840256972800 is 827965204812.

21840256972800 is a `hidden beast` number, since 2 + 1 + 8 + 4 + 0 + 2 + 569 + 72 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 164439219 + ... + 164571981.

It is an arithmetic number, because the mean of its divisors is an integer number (84268629900).

Almost surely, 2^{21840256972800} is an apocalyptic number.

21840256972800 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 21840256972800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48538730822400).

21840256972800 is an abundant number, since it is smaller than the sum of its proper divisors (75237204672000).

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

21840256972800 is a wasteful number, since it uses less digits than its factorization.

21840256972800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132828 (or 132797 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 21840256972800 in words is "twenty-one trillion, eight hundred forty billion, two hundred fifty-six million, nine hundred seventy-two thousand, eight hundred".