18566242157 has 2 divisors, whose sum is σ = 18566242158. Its totient is φ = 18566242156.

The previous prime is 18566242129. The next prime is 18566242169. The reversal of 18566242157 is 75124266581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18200438281 + 365803876 = 134909^2 + 19126^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18566242157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18566242127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9283121078 + 9283121079.

It is an arithmetic number, because the mean of its divisors is an integer number (9283121079).

Almost surely, 2^18566242157 is an apocalyptic number.

It is an amenable number.

18566242157 is a deficient number, since it is larger than the sum of its proper divisors (1).

18566242157 is an equidigital number, since it uses as much as digits as its factorization.

18566242157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 806400, while the sum is 47.

The spelling of 18566242157 in words is "eighteen billion, five hundred sixty-six million, two hundred forty-two thousand, one hundred fifty-seven".