665888329 has 2 divisors, whose sum is σ = 665888330. Its totient is φ = 665888328.

The previous prime is 665888323. The next prime is 665888347. The reversal of 665888329 is 923888566.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608855625 + 57032704 = 24675^2 + 7552^2 .

It is a cyclic number.

It is not a de Polignac number, because 665888329 - 2¹⁹ = 665364041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 665888329.

It is not a weakly prime, because it can be changed into another prime (665888323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332944164 + 332944165.

It is an arithmetic number, because the mean of its divisors is an integer number (332944165).

Almost surely, 2^665888329 is an apocalyptic number.

It is an amenable number.

665888329 is a deficient number, since it is larger than the sum of its proper divisors (1).

665888329 is an equidigital number, since it uses as much as digits as its factorization.

665888329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4976640, while the sum is 55.

The square root of 665888329 is about 25804.8121287484. The cubic root of 665888329 is about 873.2403620543.

The spelling of 665888329 in words is "six hundred sixty-five million, eight hundred eighty-eight thousand, three hundred twenty-nine".