665726 has 8 divisors (see below), whose sum is σ = 1021944. Its totient is φ = 325080.

The previous prime is 665723. The next prime is 665747. The reversal of 665726 is 627566.

665726 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×665726² = 886382214152, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 665692 and 665701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3785 + ... + 3956.

It is an arithmetic number, because the mean of its divisors is an integer number (127743).

2⁶⁶⁵⁷²⁶ is an apocalyptic number.

665726 is a deficient number, since it is larger than the sum of its proper divisors (356218).

665726 is a wasteful number, since it uses less digits than its factorization.

665726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7786.

The product of its digits is 15120, while the sum is 32.

The square root of 665726 is about 815.9203392489. The cubic root of 665726 is about 87.3169397325.

The spelling of 665726 in words is "six hundred sixty-five thousand, seven hundred twenty-six".