18508117 has 2 divisors, whose sum is σ = 18508118. Its totient is φ = 18508116.

The previous prime is 18508093. The next prime is 18508129. The reversal of 18508117 is 71180581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 5827396 = 3561^2 + 2414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18508117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18508187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9254058 + 9254059.

It is an arithmetic number, because the mean of its divisors is an integer number (9254059).

Almost surely, 2^18508117 is an apocalyptic number.

It is an amenable number.

18508117 is a deficient number, since it is larger than the sum of its proper divisors (1).

18508117 is an equidigital number, since it uses as much as digits as its factorization.

18508117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 31.

The square root of 18508117 is about 4302.1061121269. The cubic root of 18508117 is about 264.5172985733.

Adding to 18508117 its reverse (71180581), we get a palindrome (89688698).

The spelling of 18508117 in words is "eighteen million, five hundred eight thousand, one hundred seventeen".