665363189 has 2 divisors, whose sum is σ = 665363190. Its totient is φ = 665363188.

The previous prime is 665363143. The next prime is 665363191. The reversal of 665363189 is 981363566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 362255089 + 303108100 = 19033^2 + 17410^2 .

It is a cyclic number.

It is not a de Polignac number, because 665363189 - 2⁸ = 665362933 is a prime.

It is a Sophie Germain prime.

Together with 665363191, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665363989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332681594 + 332681595.

It is an arithmetic number, because the mean of its divisors is an integer number (332681595).

Almost surely, 2^665363189 is an apocalyptic number.

It is an amenable number.

665363189 is a deficient number, since it is larger than the sum of its proper divisors (1).

665363189 is an equidigital number, since it uses as much as digits as its factorization.

665363189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 47.

The square root of 665363189 is about 25794.6348878987. The cubic root of 665363189 is about 873.0107469547.

The spelling of 665363189 in words is "six hundred sixty-five million, three hundred sixty-three thousand, one hundred eighty-nine".