18404161 has 2 divisors, whose sum is σ = 18404162. Its totient is φ = 18404160.

The previous prime is 18404147. The next prime is 18404189. The reversal of 18404161 is 16140481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17850625 + 553536 = 4225^2 + 744^2 .

It is a cyclic number.

It is not a de Polignac number, because 18404161 - 2¹¹ = 18402113 is a prime.

It is a super-2 number, since 2×18404161² = 677426284227842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18444161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9202080 + 9202081.

It is an arithmetic number, because the mean of its divisors is an integer number (9202081).

Almost surely, 2^18404161 is an apocalyptic number.

It is an amenable number.

18404161 is a deficient number, since it is larger than the sum of its proper divisors (1).

18404161 is an equidigital number, since it uses as much as digits as its factorization.

18404161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 18404161 is about 4290.0071095512. The cubic root of 18404161 is about 264.0211233863.

The spelling of 18404161 in words is "eighteen million, four hundred four thousand, one hundred sixty-one".