18425009 has 2 divisors, whose sum is σ = 18425010. Its totient is φ = 18425008.

The previous prime is 18424999. The next prime is 18425021. The reversal of 18425009 is 90052481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11242609 + 7182400 = 3353^2 + 2680^2 .

It is a cyclic number.

It is not a de Polignac number, because 18425009 - 2²⁰ = 17376433 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is equal to p_1176725 and since 18425009 and 1176725 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (18425039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9212504 + 9212505.

It is an arithmetic number, because the mean of its divisors is an integer number (9212505).

Almost surely, 2^18425009 is an apocalyptic number.

It is an amenable number.

18425009 is a deficient number, since it is larger than the sum of its proper divisors (1).

18425009 is an equidigital number, since it uses as much as digits as its factorization.

18425009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 18425009 is about 4292.4362546228. The cubic root of 18425009 is about 264.1207790255.

The spelling of 18425009 in words is "eighteen million, four hundred twenty-five thousand, nine".