665391149 has 2 divisors, whose sum is σ = 665391150. Its totient is φ = 665391148.

The previous prime is 665391107. The next prime is 665391157. The reversal of 665391149 is 941193566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 513928900 + 151462249 = 22670^2 + 12307^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665391149 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 (665393149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332695574 + 332695575.

It is an arithmetic number, because the mean of its divisors is an integer number (332695575).

Almost surely, 2^665391149 is an apocalyptic number.

It is an amenable number.

665391149 is a deficient number, since it is larger than the sum of its proper divisors (1).

665391149 is an equidigital number, since it uses as much as digits as its factorization.

665391149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 174960, while the sum is 44.

The square root of 665391149 is about 25795.1768553736. The cubic root of 665391149 is about 873.0229753832.

The spelling of 665391149 in words is "six hundred sixty-five million, three hundred ninety-one thousand, one hundred forty-nine".