21164727584 has 216 divisors, whose sum is σ = 57383045244. Its totient is φ = 7610803200.

The previous prime is 21164727583. The next prime is 21164727601. The reversal of 21164727584 is 48572746112.

It can be written as a sum of positive squares in 2 ways, for example, as 14801155600 + 6363571984 = 121660^2 + 79772^2 .

It is not an unprimeable number, because it can be changed into a prime (21164727583) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2462174 + ... + 2470754.

Almost surely, 2^21164727584 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21164727584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28691522622).

21164727584 is an abundant number, since it is smaller than the sum of its proper divisors (36218317660).

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

21164727584 is a wasteful number, since it uses less digits than its factorization.

21164727584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8640 (or 8614 counting only the distinct ones).

The product of its digits is 752640, while the sum is 47.

The spelling of 21164727584 in words is "twenty-one billion, one hundred sixty-four million, seven hundred twenty-seven thousand, five hundred eighty-four".