18195689 has 2 divisors, whose sum is σ = 18195690. Its totient is φ = 18195688.

The previous prime is 18195643. The next prime is 18195713. The reversal of 18195689 is 98659181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17977600 + 218089 = 4240^2 + 467^2 .

It is an emirp because it is prime and its reverse (98659181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18195689 - 2¹⁶ = 18130153 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18195889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9097844 + 9097845.

It is an arithmetic number, because the mean of its divisors is an integer number (9097845).

Almost surely, 2^18195689 is an apocalyptic number.

It is an amenable number.

18195689 is a deficient number, since it is larger than the sum of its proper divisors (1).

18195689 is an equidigital number, since it uses as much as digits as its factorization.

18195689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 47.

The square root of 18195689 is about 4265.6405146238. The cubic root of 18195689 is about 263.0204410951.

The spelling of 18195689 in words is "eighteen million, one hundred ninety-five thousand, six hundred eighty-nine".