18066409 has 2 divisors, whose sum is σ = 18066410. Its totient is φ = 18066408.

The previous prime is 18066403. The next prime is 18066457. The reversal of 18066409 is 90466081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17640000 + 426409 = 4200^2 + 653^2 .

It is a cyclic number.

It is not a de Polignac number, because 18066409 - 2⁹ = 18065897 is a prime.

It is not a weakly prime, because it can be changed into another prime (18066403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9033204 + 9033205.

It is an arithmetic number, because the mean of its divisors is an integer number (9033205).

Almost surely, 2^18066409 is an apocalyptic number.

It is an amenable number.

18066409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18066409 is an equidigital number, since it uses as much as digits as its factorization.

18066409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 18066409 is about 4250.4598574742. The cubic root of 18066409 is about 262.3960416767.

The spelling of 18066409 in words is "eighteen million, sixty-six thousand, four hundred nine".