18513409 has 2 divisors, whose sum is σ = 18513410. Its totient is φ = 18513408.

The previous prime is 18513371. The next prime is 18513437. The reversal of 18513409 is 90431581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18490000 + 23409 = 4300^2 + 153^2 .

It is a cyclic number.

It is not a de Polignac number, because 18513409 - 2¹⁷ = 18382337 is a prime.

It is not a weakly prime, because it can be changed into another prime (18513499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9256704 + 9256705.

It is an arithmetic number, because the mean of its divisors is an integer number (9256705).

Almost surely, 2^18513409 is an apocalyptic number.

It is an amenable number.

18513409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18513409 is an equidigital number, since it uses as much as digits as its factorization.

18513409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 18513409 is about 4302.7211157592. The cubic root of 18513409 is about 264.5425071912.

The spelling of 18513409 in words is "eighteen million, five hundred thirteen thousand, four hundred nine".