18265661 has 2 divisors, whose sum is σ = 18265662. Its totient is φ = 18265660.

The previous prime is 18265619. The next prime is 18265693. The reversal of 18265661 is 16656281.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 32761 = 4270^2 + 181^2 .

It is a cyclic number.

It is not a de Polignac number, because 18265661 - 2¹⁴ = 18249277 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18265601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9132830 + 9132831.

It is an arithmetic number, because the mean of its divisors is an integer number (9132831).

Almost surely, 2^18265661 is an apocalyptic number.

It is an amenable number.

18265661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18265661 is an equidigital number, since it uses as much as digits as its factorization.

18265661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 35.

The square root of 18265661 is about 4273.8344609964. The cubic root of 18265661 is about 263.3571605138.

The spelling of 18265661 in words is "eighteen million, two hundred sixty-five thousand, six hundred sixty-one".