21560712536 has 128 divisors (see below), whose sum is σ = 50740992000. Its totient is φ = 8456140800.

The previous prime is 21560712529. The next prime is 21560712611. The reversal of 21560712536 is 63521706512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a self number, because there is not a number n which added to its sum of digits gives 21560712536.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 868910 + ... + 893378.

It is an arithmetic number, because the mean of its divisors is an integer number (396414000).

Almost surely, 2^21560712536 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 21560712536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25370496000).

21560712536 is an abundant number, since it is smaller than the sum of its proper divisors (29180279464).

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

21560712536 is a wasteful number, since it uses less digits than its factorization.

21560712536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24553 (or 24549 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 38.

The spelling of 21560712536 in words is "twenty-one billion, five hundred sixty million, seven hundred twelve thousand, five hundred thirty-six".