665713 has 2 divisors, whose sum is σ = 665714. Its totient is φ = 665712.

The previous prime is 665677. The next prime is 665719. The reversal of 665713 is 317566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 628849 + 36864 = 793^2 + 192^2 .

It is a cyclic number.

It is not a de Polignac number, because 665713 - 2⁹ = 665201 is a prime.

665713 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (665719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332856 + 332857.

It is an arithmetic number, because the mean of its divisors is an integer number (332857).

2⁶⁶⁵⁷¹³ is an apocalyptic number.

It is an amenable number.

665713 is a deficient number, since it is larger than the sum of its proper divisors (1).

665713 is an equidigital number, since it uses as much as digits as its factorization.

665713 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3780, while the sum is 28.

The square root of 665713 is about 815.9123727460. The cubic root of 665713 is about 87.3163713667.

It can be divided in two parts, 6657 and 13, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 665713 in words is "six hundred sixty-five thousand, seven hundred thirteen".