21573431326944 has 384 divisors, whose sum is σ = 72289617039360. Its totient is φ = 6131494195200.

The previous prime is 21573431326903. The next prime is 21573431326973. The reversal of 21573431326944 is 44962313437512.

21573431326944 is a `hidden beast` number, since 2 + 1 + 573 + 4 + 3 + 1 + 3 + 2 + 69 + 4 + 4 = 666.

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 polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1083374332 + ... + 1083394244.

It is an arithmetic number, because the mean of its divisors is an integer number (188254211040).

Almost surely, 2^{21573431326944} is an apocalyptic number.

21573431326944 is a gapful number since it is divisible by the number (24) 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 21573431326944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36144808519680).

21573431326944 is an abundant number, since it is smaller than the sum of its proper divisors (50716185712416).

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

21573431326944 is a wasteful number, since it uses less digits than its factorization.

21573431326944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20871 (or 20857 counting only the distinct ones).

The product of its digits is 13063680, while the sum is 54.

The spelling of 21573431326944 in words is "twenty-one trillion, five hundred seventy-three billion, four hundred thirty-one million, three hundred twenty-six thousand, nine hundred forty-four".