18509207 has 2 divisors, whose sum is σ = 18509208. Its totient is φ = 18509206.

The previous prime is 18509191. The next prime is 18509261. The reversal of 18509207 is 70290581.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18509207 - 2⁴ = 18509191 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 (18509507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9254603 + 9254604.

It is an arithmetic number, because the mean of its divisors is an integer number (9254604).

Almost surely, 2^18509207 is an apocalyptic number.

18509207 is a deficient number, since it is larger than the sum of its proper divisors (1).

18509207 is an equidigital number, since it uses as much as digits as its factorization.

18509207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 18509207 is about 4302.2327923998. The cubic root of 18509207 is about 264.5224912175.

Adding to 18509207 its reverse (70290581), we get a palindrome (88799788).

The spelling of 18509207 in words is "eighteen million, five hundred nine thousand, two hundred seven".