18012409 has 2 divisors, whose sum is σ = 18012410. Its totient is φ = 18012408.

The previous prime is 18012373. The next prime is 18012413. The reversal of 18012409 is 90421081.

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., 15578809 + 2433600 = 3947^2 + 1560^2 .

It is a cyclic number.

It is not a de Polignac number, because 18012409 - 2¹⁵ = 17979641 is a prime.

It is not a weakly prime, because it can be changed into another prime (18012419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9006204 + 9006205.

It is an arithmetic number, because the mean of its divisors is an integer number (9006205).

Almost surely, 2^18012409 is an apocalyptic number.

It is an amenable number.

18012409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18012409 is an equidigital number, since it uses as much as digits as its factorization.

18012409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 18012409 is about 4244.1028498376. The cubic root of 18012409 is about 262.1343492536.

The spelling of 18012409 in words is "eighteen million, twelve thousand, four hundred nine".