18631157 has 2 divisors, whose sum is σ = 18631158. Its totient is φ = 18631156.

The previous prime is 18631139. The next prime is 18631187. The reversal of 18631157 is 75113681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18438436 + 192721 = 4294^2 + 439^2 .

It is a cyclic number.

It is not a de Polignac number, because 18631157 - 2⁸ = 18630901 is a prime.

It is a super-2 number, since 2×18631157² = 694240022317298, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18631187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9315578 + 9315579.

It is an arithmetic number, because the mean of its divisors is an integer number (9315579).

Almost surely, 2^18631157 is an apocalyptic number.

It is an amenable number.

18631157 is a deficient number, since it is larger than the sum of its proper divisors (1).

18631157 is an equidigital number, since it uses as much as digits as its factorization.

18631157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 32.

The square root of 18631157 is about 4316.3823973323. The cubic root of 18631157 is about 265.1021654250.

The spelling of 18631157 in words is "eighteen million, six hundred thirty-one thousand, one hundred fifty-seven".