665716001 has 2 divisors, whose sum is σ = 665716002. Its totient is φ = 665716000.

The previous prime is 665715989. The next prime is 665716003. The reversal of 665716001 is 100617566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 413064976 + 252651025 = 20324^2 + 15895^2 .

It is a cyclic number.

It is not a de Polignac number, because 665716001 - 2²⁶ = 598607137 is a prime.

Together with 665716003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665716003) 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, 332858000 + 332858001.

It is an arithmetic number, because the mean of its divisors is an integer number (332858001).

Almost surely, 2^665716001 is an apocalyptic number.

It is an amenable number.

665716001 is a deficient number, since it is larger than the sum of its proper divisors (1).

665716001 is an equidigital number, since it uses as much as digits as its factorization.

665716001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 665716001 is about 25801.4728455567. The cubic root of 665716001 is about 873.1650257244.

The spelling of 665716001 in words is "six hundred sixty-five million, seven hundred sixteen thousand, one".