665743 has 8 divisors (see below), whose sum is σ = 726768. Its totient is φ = 606144.

The previous prime is 665723. The next prime is 665747. The reversal of 665743 is 347566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665743 - 2¹⁷ = 534671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 771 + ... + 1387.

It is an arithmetic number, because the mean of its divisors is an integer number (90846).

2⁶⁶⁵⁷⁴³ is an apocalyptic number.

665743 is a deficient number, since it is larger than the sum of its proper divisors (61025).

665743 is a wasteful number, since it uses less digits than its factorization.

665743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713.

The product of its digits is 15120, while the sum is 31.

The square root of 665743 is about 815.9307568660. The cubic root of 665743 is about 87.3176829689.

The spelling of 665743 in words is "six hundred sixty-five thousand, seven hundred forty-three".