18103909 has 2 divisors, whose sum is σ = 18103910. Its totient is φ = 18103908.

The previous prime is 18103879. The next prime is 18103913. The reversal of 18103909 is 90930181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16990884 + 1113025 = 4122^2 + 1055^2 .

It is a cyclic number.

It is not a de Polignac number, because 18103909 - 2¹³ = 18095717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18103949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9051954 + 9051955.

It is an arithmetic number, because the mean of its divisors is an integer number (9051955).

Almost surely, 2^18103909 is an apocalyptic number.

It is an amenable number.

18103909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18103909 is an equidigital number, since it uses as much as digits as its factorization.

18103909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18103909 is about 4254.8688581436. The cubic root of 18103909 is about 262.5774658747.

The spelling of 18103909 in words is "eighteen million, one hundred three thousand, nine hundred nine".