18365549 has 2 divisors, whose sum is σ = 18365550. Its totient is φ = 18365548.

The previous prime is 18365539. The next prime is 18365563. The reversal of 18365549 is 94556381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16752649 + 1612900 = 4093^2 + 1270^2 .

It is a cyclic number.

It is not a de Polignac number, because 18365549 - 2²⁴ = 1588333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18365509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9182774 + 9182775.

It is an arithmetic number, because the mean of its divisors is an integer number (9182775).

Almost surely, 2^18365549 is an apocalyptic number.

It is an amenable number.

18365549 is a deficient number, since it is larger than the sum of its proper divisors (1).

18365549 is an equidigital number, since it uses as much as digits as its factorization.

18365549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 41.

The square root of 18365549 is about 4285.5045210570. The cubic root of 18365549 is about 263.8363550030.

The spelling of 18365549 in words is "eighteen million, three hundred sixty-five thousand, five hundred forty-nine".