869639 has 4 divisors (see below), whose sum is σ = 873120. Its totient is φ = 866160.

The previous prime is 869599. The next prime is 869657. The reversal of 869639 is 936968.

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-869639 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 869596 and 869605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869689) 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, 1334 + ... + 1875.

It is an arithmetic number, because the mean of its divisors is an integer number (218280).

2⁸⁶⁹⁶³⁹ is an apocalyptic number.

869639 is a deficient number, since it is larger than the sum of its proper divisors (3481).

869639 is a wasteful number, since it uses less digits than its factorization.

869639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3480.

The product of its digits is 69984, while the sum is 41.

The square root of 869639 is about 932.5443689176. The cubic root of 869639 is about 95.4508212386.

The spelling of 869639 in words is "eight hundred sixty-nine thousand, six hundred thirty-nine".