21758091264 has 896 divisors, whose sum is σ = 84552007680. Its totient is φ = 5372116992.

The previous prime is 21758091263. The next prime is 21758091293. The reversal of 21758091264 is 46219085712.

21758091264 is a `hidden beast` number, since 2 + 1 + 7 + 580 + 9 + 1 + 2 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (896).

It is not an unprimeable number, because it can be changed into a prime (21758091263) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 462938089 + ... + 462938135.

It is an arithmetic number, because the mean of its divisors is an integer number (94366080).

Almost surely, 2^21758091264 is an apocalyptic number.

21758091264 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 21758091264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42276003840).

21758091264 is an abundant number, since it is smaller than the sum of its proper divisors (62793916416).

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

21758091264 is a wasteful number, since it uses less digits than its factorization.

21758091264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 21758091264 in words is "twenty-one billion, seven hundred fifty-eight million, ninety-one thousand, two hundred sixty-four".