18157157 has 4 divisors (see below), whose sum is σ = 18361260. Its totient is φ = 17953056.

The previous prime is 18157147. The next prime is 18157159. The reversal of 18157157 is 75175181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9431041 + 8726116 = 3071^2 + 2954^2 .

It is a cyclic number.

It is not a de Polignac number, because 18157157 - 2¹⁰ = 18156133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18157159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101918 + ... + 102095.

It is an arithmetic number, because the mean of its divisors is an integer number (4590315).

Almost surely, 2^18157157 is an apocalyptic number.

It is an amenable number.

18157157 is a deficient number, since it is larger than the sum of its proper divisors (204103).

18157157 is an equidigital number, since it uses as much as digits as its factorization.

18157157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204102.

The product of its digits is 9800, while the sum is 35.

The square root of 18157157 is about 4261.1215659730. The cubic root of 18157157 is about 262.8346486259.

The spelling of 18157157 in words is "eighteen million, one hundred fifty-seven thousand, one hundred fifty-seven".