21134719565 has 16 divisors (see below), whose sum is σ = 25986680496. Its totient is φ = 16491302400.

The previous prime is 21134719517. The next prime is 21134719603. The reversal of 21134719565 is 56591743112.

It can be written as a sum of positive squares in 8 ways, for example, as 9259849 + 21125459716 = 3043^2 + 145346^2 .

It is not a de Polignac number, because 21134719565 - 2²⁶ = 21067610701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1019039 + ... + 1039571.

It is an arithmetic number, because the mean of its divisors is an integer number (1624167531).

Almost surely, 2^21134719565 is an apocalyptic number.

It is an amenable number.

21134719565 is a deficient number, since it is larger than the sum of its proper divisors (4851960931).

21134719565 is a wasteful number, since it uses less digits than its factorization.

21134719565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25600.

The product of its digits is 226800, while the sum is 44.

The spelling of 21134719565 in words is "twenty-one billion, one hundred thirty-four million, seven hundred nineteen thousand, five hundred sixty-five".