665838 has 24 divisors (see below), whose sum is σ = 1465776. Its totient is φ = 218400.

The previous prime is 665813. The next prime is 665843. The reversal of 665838 is 838566.

665838 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1018 + ... + 1538.

It is an arithmetic number, because the mean of its divisors is an integer number (61074).

2⁶⁶⁵⁸³⁸ is an apocalyptic number.

665838 is an abundant number, since it is smaller than the sum of its proper divisors (799938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665838 is a wasteful number, since it uses less digits than its factorization.

665838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600 (or 597 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 665838 is about 815.9889705137. The cubic root of 665838 is about 87.3218361157.

The spelling of 665838 in words is "six hundred sixty-five thousand, eight hundred thirty-eight".