18693209 has 2 divisors, whose sum is σ = 18693210. Its totient is φ = 18693208.

The previous prime is 18693193. The next prime is 18693247. The reversal of 18693209 is 90239681.

It is an a-pointer prime, because the next prime (18693247) can be obtained adding 18693209 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18619225 + 73984 = 4315^2 + 272^2 .

It is a cyclic number.

It is not a de Polignac number, because 18693209 - 2⁴ = 18693193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18693109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9346604 + 9346605.

It is an arithmetic number, because the mean of its divisors is an integer number (9346605).

Almost surely, 2^18693209 is an apocalyptic number.

It is an amenable number.

18693209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18693209 is an equidigital number, since it uses as much as digits as its factorization.

18693209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 18693209 is about 4323.5643860130. The cubic root of 18693209 is about 265.3961512938.

The spelling of 18693209 in words is "eighteen million, six hundred ninety-three thousand, two hundred nine".