21017525760 has 960 divisors, whose sum is σ = 94043980800. Its totient is φ = 4355112960.

The previous prime is 21017525701. The next prime is 21017525779. The reversal of 21017525760 is 6752571012.

21017525760 is a `hidden beast` number, since 2 + 10 + 1 + 75 + 2 + 576 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 95 ways as a sum of consecutive naturals, for example, 58544461 + ... + 58544819.

It is an arithmetic number, because the mean of its divisors is an integer number (97962480).

Almost surely, 2^21017525760 is an apocalyptic number.

21017525760 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 21017525760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47021990400).

21017525760 is an abundant number, since it is smaller than the sum of its proper divisors (73026455040).

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

21017525760 is a wasteful number, since it uses less digits than its factorization.

21017525760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The spelling of 21017525760 in words is "twenty-one billion, seventeen million, five hundred twenty-five thousand, seven hundred sixty".