18506417 has 2 divisors, whose sum is σ = 18506418. Its totient is φ = 18506416.

The previous prime is 18506407. The next prime is 18506419. The reversal of 18506417 is 71460581.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16289296 + 2217121 = 4036^2 + 1489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18506417 is a prime.

Together with 18506419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18506419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9253208 + 9253209.

It is an arithmetic number, because the mean of its divisors is an integer number (9253209).

Almost surely, 2^18506417 is an apocalyptic number.

It is an amenable number.

18506417 is a deficient number, since it is larger than the sum of its proper divisors (1).

18506417 is an equidigital number, since it uses as much as digits as its factorization.

18506417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 18506417 is about 4301.9085299434. The cubic root of 18506417 is about 264.5091995471.

Adding to 18506417 its reverse (71460581), we get a palindrome (89966998).

The spelling of 18506417 in words is "eighteen million, five hundred six thousand, four hundred seventeen".