18409109 has 2 divisors, whose sum is σ = 18409110. Its totient is φ = 18409108.

The previous prime is 18409051. The next prime is 18409163. The reversal of 18409109 is 90190481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18037009 + 372100 = 4247^2 + 610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18409109 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 (18409199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9204554 + 9204555.

It is an arithmetic number, because the mean of its divisors is an integer number (9204555).

Almost surely, 2^18409109 is an apocalyptic number.

It is an amenable number.

18409109 is a deficient number, since it is larger than the sum of its proper divisors (1).

18409109 is an equidigital number, since it uses as much as digits as its factorization.

18409109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 18409109 is about 4290.5837598164. The cubic root of 18409109 is about 264.0447821568.

The spelling of 18409109 in words is "eighteen million, four hundred nine thousand, one hundred nine".