665723 has 2 divisors, whose sum is σ = 665724. Its totient is φ = 665722.

The previous prime is 665719. The next prime is 665747. The reversal of 665723 is 327566.

665723 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665723 - 2² = 665719 is a prime.

It is a super-2 number, since 2×665723² = 886374225458, which contains 22 as substring.

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, 332861 + 332862.

It is an arithmetic number, because the mean of its divisors is an integer number (332862).

2⁶⁶⁵⁷²³ is an apocalyptic number.

665723 is a deficient number, since it is larger than the sum of its proper divisors (1).

665723 is an equidigital number, since it uses as much as digits as its factorization.

665723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 29.

The square root of 665723 is about 815.9185008320. The cubic root of 665723 is about 87.3168085718.

The spelling of 665723 in words is "six hundred sixty-five thousand, seven hundred twenty-three".