18197667157 has 2 divisors, whose sum is σ = 18197667158. Its totient is φ = 18197667156.

The previous prime is 18197667149. The next prime is 18197667161. The reversal of 18197667157 is 75176679181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18087291121 + 110376036 = 134489^2 + 10506^2 .

It is a cyclic number.

It is not a de Polignac number, because 18197667157 - 2³ = 18197667149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18197667197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9098833578 + 9098833579.

It is an arithmetic number, because the mean of its divisors is an integer number (9098833579).

Almost surely, 2^18197667157 is an apocalyptic number.

It is an amenable number.

18197667157 is a deficient number, since it is larger than the sum of its proper divisors (1).

18197667157 is an equidigital number, since it uses as much as digits as its factorization.

18197667157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4445280, while the sum is 58.

The spelling of 18197667157 in words is "eighteen billion, one hundred ninety-seven million, six hundred sixty-seven thousand, one hundred fifty-seven".