18617161 has 2 divisors, whose sum is σ = 18617162. Its totient is φ = 18617160.

The previous prime is 18617153. The next prime is 18617171. The reversal of 18617161 is 16171681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12145225 + 6471936 = 3485^2 + 2544^2 .

It is an emirp because it is prime and its reverse (16171681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18617161 - 2³ = 18617153 is a prime.

It is not a weakly prime, because it can be changed into another prime (18617141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9308580 + 9308581.

It is an arithmetic number, because the mean of its divisors is an integer number (9308581).

Almost surely, 2^18617161 is an apocalyptic number.

It is an amenable number.

18617161 is a deficient number, since it is larger than the sum of its proper divisors (1).

18617161 is an equidigital number, since it uses as much as digits as its factorization.

18617161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 31.

The square root of 18617161 is about 4314.7608276705. The cubic root of 18617161 is about 265.0357659095.

The spelling of 18617161 in words is "eighteen million, six hundred seventeen thousand, one hundred sixty-one".