865506 has 16 divisors (see below), whose sum is σ = 1757664. Its totient is φ = 284064.

The previous prime is 865499. The next prime is 865511. The reversal of 865506 is 605568.

865506 = 79² + 80² + ... + 145².

865506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

865506 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 7 ways as a sum of consecutive naturals, for example, 675 + ... + 1478.

It is an arithmetic number, because the mean of its divisors is an integer number (109854).

2⁸⁶⁵⁵⁰⁶ is an apocalyptic number.

865506 is an abundant number, since it is smaller than the sum of its proper divisors (892158).

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

865506 is a wasteful number, since it uses less digits than its factorization.

865506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2225.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 865506 is about 930.3257494018. The cubic root of 865506 is about 95.2993695609.

The spelling of 865506 in words is "eight hundred sixty-five thousand, five hundred six".