868591 has 4 divisors (see below), whose sum is σ = 870552. Its totient is φ = 866632.

The previous prime is 868583. The next prime is 868603. The reversal of 868591 is 195868.

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

It is a cyclic number.

It is not a de Polignac number, because 868591 - 2³ = 868583 is a prime.

It is a Duffinian number.

868591 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 868591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (868531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36 + ... + 1318.

It is an arithmetic number, because the mean of its divisors is an integer number (217638).

2⁸⁶⁸⁵⁹¹ is an apocalyptic number.

868591 is a deficient number, since it is larger than the sum of its proper divisors (1961).

868591 is a wasteful number, since it uses less digits than its factorization.

868591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1960.

The product of its digits is 17280, while the sum is 37.

The square root of 868591 is about 931.9822959692. The cubic root of 868591 is about 95.4124633029.

The spelling of 868591 in words is "eight hundred sixty-eight thousand, five hundred ninety-one".