18304217 has 2 divisors, whose sum is σ = 18304218. Its totient is φ = 18304216.

The previous prime is 18304213. The next prime is 18304259. The reversal of 18304217 is 71240381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18011536 + 292681 = 4244^2 + 541^2 .

It is an emirp because it is prime and its reverse (71240381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18304217 - 2² = 18304213 is a prime.

It is not a weakly prime, because it can be changed into another prime (18304211) 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, 9152108 + 9152109.

It is an arithmetic number, because the mean of its divisors is an integer number (9152109).

Almost surely, 2^18304217 is an apocalyptic number.

It is an amenable number.

18304217 is a deficient number, since it is larger than the sum of its proper divisors (1).

18304217 is an equidigital number, since it uses as much as digits as its factorization.

18304217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 18304217 is about 4278.3427866406. The cubic root of 18304217 is about 263.5423324335.

Adding to 18304217 its reverse (71240381), we get a palindrome (89544598).

The spelling of 18304217 in words is "eighteen million, three hundred four thousand, two hundred seventeen".