665256 has 32 divisors (see below), whose sum is σ = 1697760. Its totient is φ = 217152.

The previous prime is 665251. The next prime is 665267. The reversal of 665256 is 652566.

It is not an unprimeable number, because it can be changed into a prime (665251) 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, 1011 + ... + 1533.

It is an arithmetic number, because the mean of its divisors is an integer number (53055).

2⁶⁶⁵²⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (848880).

665256 is an abundant number, since it is smaller than the sum of its proper divisors (1032504).

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

665256 is a wasteful number, since it uses less digits than its factorization.

665256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585 (or 581 counting only the distinct ones).

The product of its digits is 10800, while the sum is 30.

The square root of 665256 is about 815.6322700825. The cubic root of 665256 is about 87.2963864202.

Subtracting from 665256 its product of digits (10800), we obtain a palindrome (654456).

The spelling of 665256 in words is "six hundred sixty-five thousand, two hundred fifty-six".