18730909 has 2 divisors, whose sum is σ = 18730910. Its totient is φ = 18730908.

The previous prime is 18730871. The next prime is 18730919. The reversal of 18730909 is 90903781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14516100 + 4214809 = 3810^2 + 2053^2 .

It is a cyclic number.

It is not a de Polignac number, because 18730909 - 2¹¹ = 18728861 is a prime.

It is equal to p_1194976 and since 18730909 and 1194976 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18730919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9365454 + 9365455.

It is an arithmetic number, because the mean of its divisors is an integer number (9365455).

Almost surely, 2^18730909 is an apocalyptic number.

It is an amenable number.

18730909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18730909 is an equidigital number, since it uses as much as digits as its factorization.

18730909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 18730909 is about 4327.9220187060. The cubic root of 18730909 is about 265.5744462777.

The spelling of 18730909 in words is "eighteen million, seven hundred thirty thousand, nine hundred nine".