665837 has 4 divisors (see below), whose sum is σ = 670236. Its totient is φ = 661440.

The previous prime is 665813. The next prime is 665843. The reversal of 665837 is 738566.

It is a happy number.

665837 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 738566 = 2 ⋅369283.

It can be written as a sum of positive squares in 2 ways, for example, as 477481 + 188356 = 691^2 + 434^2 .

It is a cyclic number.

It is not a de Polignac number, because 665837 - 2⁶ = 665773 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665797 and 665806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665857) 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, 1964 + ... + 2277.

It is an arithmetic number, because the mean of its divisors is an integer number (167559).

2⁶⁶⁵⁸³⁷ is an apocalyptic number.

It is an amenable number.

665837 is a deficient number, since it is larger than the sum of its proper divisors (4399).

665837 is a wasteful number, since it uses less digits than its factorization.

665837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4398.

The product of its digits is 30240, while the sum is 35.

The square root of 665837 is about 815.9883577601. The cubic root of 665837 is about 87.3217924005.

The spelling of 665837 in words is "six hundred sixty-five thousand, eight hundred thirty-seven".