18311987825 has 12 divisors (see below), whose sum is σ = 23091728880. Its totient is φ = 14401290960.

The previous prime is 18311987821. The next prime is 18311987839. The reversal of 18311987825 is 52878911381.

It is not a de Polignac number, because 18311987825 - 2² = 18311987821 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18311987821) 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, 6205979 + ... + 6208928.

It is an arithmetic number, because the mean of its divisors is an integer number (1924310740).

Almost surely, 2^18311987825 is an apocalyptic number.

It is an amenable number.

18311987825 is a deficient number, since it is larger than the sum of its proper divisors (4779741055).

18311987825 is a wasteful number, since it uses less digits than its factorization.

18311987825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12414976 (or 12414971 counting only the distinct ones).

The product of its digits is 967680, while the sum is 53.

The spelling of 18311987825 in words is "eighteen billion, three hundred eleven million, nine hundred eighty-seven thousand, eight hundred twenty-five".