665826 has 32 divisors (see below), whose sum is σ = 1548288. Its totient is φ = 186960.

The previous prime is 665813. The next prime is 665843. The reversal of 665826 is 628566.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665826.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3391 + ... + 3581.

It is an arithmetic number, because the mean of its divisors is an integer number (48384).

2⁶⁶⁵⁸²⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665826, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (774144).

665826 is an abundant number, since it is smaller than the sum of its proper divisors (882462).

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

665826 is a wasteful number, since it uses less digits than its factorization.

665826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286.

The product of its digits is 17280, while the sum is 33.

The square root of 665826 is about 815.9816174400. The cubic root of 665826 is about 87.3213115295.

The spelling of 665826 in words is "six hundred sixty-five thousand, eight hundred twenty-six".