665719 has 2 divisors, whose sum is σ = 665720. Its totient is φ = 665718.

The previous prime is 665713. The next prime is 665723. The reversal of 665719 is 917566.

665719 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665719 - 2⁷ = 665591 is a prime.

It is a super-2 number, since 2×665719² = 886363573922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332859 + 332860.

It is an arithmetic number, because the mean of its divisors is an integer number (332860).

2⁶⁶⁵⁷¹⁹ is an apocalyptic number.

665719 is a deficient number, since it is larger than the sum of its proper divisors (1).

665719 is an equidigital number, since it uses as much as digits as its factorization.

665719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 34.

The square root of 665719 is about 815.9160496031. The cubic root of 665719 is about 87.3166336903.

The spelling of 665719 in words is "six hundred sixty-five thousand, seven hundred nineteen".