665728559 has 2 divisors, whose sum is σ = 665728560. Its totient is φ = 665728558.

The previous prime is 665728543. The next prime is 665728607. The reversal of 665728559 is 955827566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665728559 - 2⁴ = 665728543 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 665728559.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665728529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332864279 + 332864280.

It is an arithmetic number, because the mean of its divisors is an integer number (332864280).

Almost surely, 2^665728559 is an apocalyptic number.

665728559 is a deficient number, since it is larger than the sum of its proper divisors (1).

665728559 is an equidigital number, since it uses as much as digits as its factorization.

665728559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536000, while the sum is 53.

The square root of 665728559 is about 25801.7162026095. The cubic root of 665728559 is about 873.1705161224.

The spelling of 665728559 in words is "six hundred sixty-five million, seven hundred twenty-eight thousand, five hundred fifty-nine".