21585816596 has 6 divisors (see below), whose sum is σ = 37775179050. Its totient is φ = 10792908296.

The previous prime is 21585816583. The next prime is 21585816599. The reversal of 21585816596 is 69561858512.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21209844496 + 375972100 = 145636^2 + 19390^2 .

It is a super-2 number, since 2×21585816596² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21585816599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2698227071 + ... + 2698227078.

It is an arithmetic number, because the mean of its divisors is an integer number (6295863175).

Almost surely, 2^21585816596 is an apocalyptic number.

It is an amenable number.

21585816596 is a deficient number, since it is larger than the sum of its proper divisors (16189362454).

21585816596 is a wasteful number, since it uses less digits than its factorization.

21585816596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5396454153 (or 5396454151 counting only the distinct ones).

The product of its digits is 5184000, while the sum is 56.

The spelling of 21585816596 in words is "twenty-one billion, five hundred eighty-five million, eight hundred sixteen thousand, five hundred ninety-six".