18661590825 has 12 divisors (see below), whose sum is σ = 30853830288. Its totient is φ = 9952848400.

The previous prime is 18661590821. The next prime is 18661590853. The reversal of 18661590825 is 52809516681.

It is not a de Polignac number, because 18661590825 - 2² = 18661590821 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18661590821) 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, 124410531 + ... + 124410680.

It is an arithmetic number, because the mean of its divisors is an integer number (2571152524).

Almost surely, 2^18661590825 is an apocalyptic number.

18661590825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18661590825 is a deficient number, since it is larger than the sum of its proper divisors (12192239463).

18661590825 is a wasteful number, since it uses less digits than its factorization.

18661590825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248821224 (or 248821219 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 51.

The spelling of 18661590825 in words is "eighteen billion, six hundred sixty-one million, five hundred ninety thousand, eight hundred twenty-five".