18561572825 has 12 divisors (see below), whose sum is σ = 24370253820. Its totient is φ = 13975772160.

The previous prime is 18561572789. The next prime is 18561572839. The reversal of 18561572825 is 52827516581.

It can be written as a sum of positive squares in 6 ways, for example, as 454371856 + 18107200969 = 21316^2 + 134563^2 .

It is not a de Polignac number, because 18561572825 - 2⁸ = 18561572569 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21836720 + ... + 21837569.

It is an arithmetic number, because the mean of its divisors is an integer number (2030854485).

Almost surely, 2^18561572825 is an apocalyptic number.

It is an amenable number.

18561572825 is a deficient number, since it is larger than the sum of its proper divisors (5808680995).

18561572825 is a wasteful number, since it uses less digits than its factorization.

18561572825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43674316 (or 43674311 counting only the distinct ones).

The product of its digits is 1344000, while the sum is 50.

The spelling of 18561572825 in words is "eighteen billion, five hundred sixty-one million, five hundred seventy-two thousand, eight hundred twenty-five".