18618169 has 2 divisors, whose sum is σ = 18618170. Its totient is φ = 18618168.

The previous prime is 18618137. The next prime is 18618191. The reversal of 18618169 is 96181681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11648569 + 6969600 = 3413^2 + 2640^2 .

It is an emirp because it is prime and its reverse (96181681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18618169 - 2⁵ = 18618137 is a prime.

It is a super-2 number, since 2×18618169² = 693272433825122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18618199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9309084 + 9309085.

It is an arithmetic number, because the mean of its divisors is an integer number (9309085).

Almost surely, 2^18618169 is an apocalyptic number.

It is an amenable number.

18618169 is a deficient number, since it is larger than the sum of its proper divisors (1).

18618169 is an equidigital number, since it uses as much as digits as its factorization.

18618169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 40.

The square root of 18618169 is about 4314.8776344179. The cubic root of 18618169 is about 265.0405491528.

The spelling of 18618169 in words is "eighteen million, six hundred eighteen thousand, one hundred sixty-nine".