18518417 has 2 divisors, whose sum is σ = 18518418. Its totient is φ = 18518416.

The previous prime is 18518413. The next prime is 18518431. The reversal of 18518417 is 71481581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12559936 + 5958481 = 3544^2 + 2441^2 .

It is an emirp because it is prime and its reverse (71481581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18518417 - 2² = 18518413 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18518413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9259208 + 9259209.

It is an arithmetic number, because the mean of its divisors is an integer number (9259209).

Almost surely, 2^18518417 is an apocalyptic number.

It is an amenable number.

18518417 is a deficient number, since it is larger than the sum of its proper divisors (1).

18518417 is an equidigital number, since it uses as much as digits as its factorization.

18518417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8960, while the sum is 35.

The square root of 18518417 is about 4303.3030337172. The cubic root of 18518417 is about 264.5663585420.

Adding to 18518417 its reverse (71481581), we get a palindrome (89999998).

The spelling of 18518417 in words is "eighteen million, five hundred eighteen thousand, four hundred seventeen".