21337585065 has 12 divisors (see below), whose sum is σ = 36985147524. Its totient is φ = 11380045344.

The previous prime is 21337585051. The next prime is 21337585069. The reversal of 21337585065 is 56058573312.

21337585065 is a `hidden beast` number, since 2 + 1 + 3 + 3 + 7 + 585 + 0 + 65 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3345118569 + 17992466496 = 57837^2 + 134136^2 .

It is not a de Polignac number, because 21337585065 - 2⁵ = 21337585033 is a prime.

It is a super-2 number, since 2×21337585065² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 474168557 = 21337585065 / (2 + 1 + 3 + 3 + 7 + 5 + 8 + 5 + 0 + 6 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 21337585065.

It is not an unprimeable number, because it can be changed into a prime (21337585069) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 237084234 + ... + 237084323.

It is an arithmetic number, because the mean of its divisors is an integer number (3082095627).

Almost surely, 2^21337585065 is an apocalyptic number.

It is an amenable number.

21337585065 is a deficient number, since it is larger than the sum of its proper divisors (15647562459).

21337585065 is a wasteful number, since it uses less digits than its factorization.

21337585065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474168568 (or 474168565 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 45.

The spelling of 21337585065 in words is "twenty-one billion, three hundred thirty-seven million, five hundred eighty-five thousand, sixty-five".