865523 has 4 divisors (see below), whose sum is σ = 873720. Its totient is φ = 857328.

The previous prime is 865511. The next prime is 865537. The reversal of 865523 is 325568.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-865523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (805523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3938 + ... + 4151.

It is an arithmetic number, because the mean of its divisors is an integer number (218430).

2⁸⁶⁵⁵²³ is an apocalyptic number.

865523 is a deficient number, since it is larger than the sum of its proper divisors (8197).

865523 is a wasteful number, since it uses less digits than its factorization.

865523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8196.

The product of its digits is 7200, while the sum is 29.

The square root of 865523 is about 930.3348859416. The cubic root of 865523 is about 95.2999935037.

The spelling of 865523 in words is "eight hundred sixty-five thousand, five hundred twenty-three".