665756 has 48 divisors (see below), whose sum is σ = 1505280. Its totient is φ = 250560.

The previous prime is 665747. The next prime is 665761. The reversal of 665756 is 657566.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

665756 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11255 + ... + 11313.

It is an arithmetic number, because the mean of its divisors is an integer number (31360).

2⁶⁶⁵⁷⁵⁶ 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 665756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (752640).

665756 is an abundant number, since it is smaller than the sum of its proper divisors (839524).

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

665756 is a wasteful number, since it uses less digits than its factorization.

665756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 112 counting only the distinct ones).

The product of its digits is 37800, while the sum is 35.

The square root of 665756 is about 815.9387231894. The cubic root of 665756 is about 87.3182513176.

The spelling of 665756 in words is "six hundred sixty-five thousand, seven hundred fifty-six".