25536644018 has 6 divisors (see below), whose sum is σ = 38305305021. Its totient is φ = 12768209012.

The previous prime is 25536643991. The next prime is 25536644051. The reversal of 25536644018 is 81044663552.

It can be written as a sum of positive squares in 2 ways, for example, as 25012371409 + 524272609 = 158153^2 + 22897^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=112997.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25536644018.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 169496 + ... + 282492.

Almost surely, 2^25536644018 is an apocalyptic number.

25536644018 is a deficient number, since it is larger than the sum of its proper divisors (12768661003).

25536644018 is an frugal number, since it uses more digits than its factorization.

25536644018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225996 (or 112999 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 44.

The spelling of 25536644018 in words is "twenty-five billion, five hundred thirty-six million, six hundred forty-four thousand, eighteen".