18306217 has 2 divisors, whose sum is σ = 18306218. Its totient is φ = 18306216.

The previous prime is 18306203. The next prime is 18306247. The reversal of 18306217 is 71260381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9803161 + 8503056 = 3131^2 + 2916^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18306217 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18306247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9153108 + 9153109.

It is an arithmetic number, because the mean of its divisors is an integer number (9153109).

Almost surely, 2^18306217 is an apocalyptic number.

It is an amenable number.

18306217 is a deficient number, since it is larger than the sum of its proper divisors (1).

18306217 is an equidigital number, since it uses as much as digits as its factorization.

18306217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 18306217 is about 4278.5765156182. The cubic root of 18306217 is about 263.5519306856.

Adding to 18306217 its reverse (71260381), we get a palindrome (89566598).

The spelling of 18306217 in words is "eighteen million, three hundred six thousand, two hundred seventeen".