21579615752 has 36 divisors (see below), whose sum is σ = 40836823215. Its totient is φ = 10690712080.

The previous prime is 21579615751. The next prime is 21579615779. The reversal of 21579615752 is 25751697512.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 10789807876 + 10789807876 = 103874^2 + 103874^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103874.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21579615752.

It is not an unprimeable number, because it can be changed into a prime (21579615751) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 69387677 + ... + 69387987.

Almost surely, 2^21579615752 is an apocalyptic number.

It is an amenable number.

21579615752 is a deficient number, since it is larger than the sum of its proper divisors (19257207463).

21579615752 is an frugal number, since it uses more digits than its factorization.

21579615752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 962 (or 480 counting only the distinct ones).

The product of its digits is 1323000, while the sum is 50.

Multiplying 21579615752 by its sum of digits (50), we get a square (1078980787600 = 1038740²).

The spelling of 21579615752 in words is "twenty-one billion, five hundred seventy-nine million, six hundred fifteen thousand, seven hundred fifty-two".