665061289 has 2 divisors, whose sum is σ = 665061290. Its totient is φ = 665061288.

The previous prime is 665061283. The next prime is 665061359. The reversal of 665061289 is 982160566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 538611264 + 126450025 = 23208^2 + 11245^2 .

It is a cyclic number.

It is not a de Polignac number, because 665061289 - 2²⁷ = 530843561 is a prime.

It is not a weakly prime, because it can be changed into another prime (665061283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332530644 + 332530645.

It is an arithmetic number, because the mean of its divisors is an integer number (332530645).

Almost surely, 2^665061289 is an apocalyptic number.

It is an amenable number.

665061289 is a deficient number, since it is larger than the sum of its proper divisors (1).

665061289 is an equidigital number, since it uses as much as digits as its factorization.

665061289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 665061289 is about 25788.7822318154. The cubic root of 665061289 is about 872.8786878420.

The spelling of 665061289 in words is "six hundred sixty-five million, sixty-one thousand, two hundred eighty-nine".