865669 has 4 divisors (see below), whose sum is σ = 989344. Its totient is φ = 741996.

The previous prime is 865661. The next prime is 865681. The reversal of 865669 is 966568.

865669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 865669 - 2³ = 865661 is a prime.

It is a super-2 number, since 2×865669² = 1498765635122, which contains 22 as substring.

It is a Duffinian number.

865669 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865661) 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, 61827 + ... + 61840.

It is an arithmetic number, because the mean of its divisors is an integer number (247336).

2⁸⁶⁵⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

865669 is a deficient number, since it is larger than the sum of its proper divisors (123675).

865669 is a wasteful number, since it uses less digits than its factorization.

865669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123674.

The product of its digits is 77760, while the sum is 40.

The square root of 865669 is about 930.4133490014. The cubic root of 865669 is about 95.3053517348.

The spelling of 865669 in words is "eight hundred sixty-five thousand, six hundred sixty-nine".