18945217 has 2 divisors, whose sum is σ = 18945218. Its totient is φ = 18945216.

The previous prime is 18945161. The next prime is 18945233. The reversal of 18945217 is 71254981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14622976 + 4322241 = 3824^2 + 2079^2 .

It is a cyclic number.

It is not a de Polignac number, because 18945217 - 2¹⁹ = 18420929 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18945257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9472608 + 9472609.

It is an arithmetic number, because the mean of its divisors is an integer number (9472609).

Almost surely, 2^18945217 is an apocalyptic number.

It is an amenable number.

18945217 is a deficient number, since it is larger than the sum of its proper divisors (1).

18945217 is an equidigital number, since it uses as much as digits as its factorization.

18945217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 18945217 is about 4352.6103662055. The cubic root of 18945217 is about 266.5834565032.

The spelling of 18945217 in words is "eighteen million, nine hundred forty-five thousand, two hundred seventeen".