18912317 has 2 divisors, whose sum is σ = 18912318. Its totient is φ = 18912316.

The previous prime is 18912293. The next prime is 18912331. The reversal of 18912317 is 71321981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15888196 + 3024121 = 3986^2 + 1739^2 .

It is a cyclic number.

It is not a de Polignac number, because 18912317 - 2²² = 14718013 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 (18912337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9456158 + 9456159.

It is an arithmetic number, because the mean of its divisors is an integer number (9456159).

Almost surely, 2^18912317 is an apocalyptic number.

It is an amenable number.

18912317 is a deficient number, since it is larger than the sum of its proper divisors (1).

18912317 is an equidigital number, since it uses as much as digits as its factorization.

18912317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 18912317 is about 4348.8293827190. The cubic root of 18912317 is about 266.4290520505.

The spelling of 18912317 in words is "eighteen million, nine hundred twelve thousand, three hundred seventeen".