21095238564 has 45 divisors (see below), whose sum is σ = 55153955857. Its totient is φ = 7030874736.

The previous prime is 21095238559. The next prime is 21095238581. The reversal of 21095238564 is 46583259012.

The square root of 21095238564 is 145242.

It is a perfect power (a square), and thus also a powerful number.

21095238564 is a `hidden beast` number, since 2 + 1 + 0 + 9 + 52 + 38 + 564 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47032164 + 21048206400 = 6858^2 + 145080^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2610322 + ... + 2618390.

Almost surely, 2^21095238564 is an apocalyptic number.

21095238564 is the 145242-nd square number.

It is an amenable number.

21095238564 is an abundant number, since it is smaller than the sum of its proper divisors (34058717293).

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

21095238564 is an frugal number, since it uses more digits than its factorization.

21095238564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16154 (or 8074 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 21095238564 in words is "twenty-one billion, ninety-five million, two hundred thirty-eight thousand, five hundred sixty-four".