21595790464 has 16 divisors (see below), whose sum is σ = 43022864070. Its totient is φ = 10797895168.

The previous prime is 21595790443. The next prime is 21595790467. The reversal of 21595790464 is 46409759512.

It can be written as a sum of positive squares in only one way, i.e., 16972878400 + 4622912064 = 130280^2 + 67992^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (21595790467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84358429 + ... + 84358684.

Almost surely, 2^21595790464 is an apocalyptic number.

It is an amenable number.

21595790464 is a deficient number, since it is larger than the sum of its proper divisors (21427073606).

21595790464 is an equidigital number, since it uses as much as digits as its factorization.

21595790464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168717127 (or 168717115 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 52.

The spelling of 21595790464 in words is "twenty-one billion, five hundred ninety-five million, seven hundred ninety thousand, four hundred sixty-four".