18645917 has 2 divisors, whose sum is σ = 18645918. Its totient is φ = 18645916.

The previous prime is 18645883. The next prime is 18645941. The reversal of 18645917 is 71954681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16168441 + 2477476 = 4021^2 + 1574^2 .

It is an emirp because it is prime and its reverse (71954681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18645917 - 2²⁴ = 1868701 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18645967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9322958 + 9322959.

It is an arithmetic number, because the mean of its divisors is an integer number (9322959).

Almost surely, 2^18645917 is an apocalyptic number.

It is an amenable number.

18645917 is a deficient number, since it is larger than the sum of its proper divisors (1).

18645917 is an equidigital number, since it uses as much as digits as its factorization.

18645917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 41.

The square root of 18645917 is about 4318.0918239426. The cubic root of 18645917 is about 265.1721534763.

The spelling of 18645917 in words is "eighteen million, six hundred forty-five thousand, nine hundred seventeen".