863891 has 8 divisors (see below), whose sum is σ = 994560. Its totient is φ = 735048.

The previous prime is 863887. The next prime is 863897. The reversal of 863891 is 198368.

863891 is nontrivially palindromic in base 8.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 863891 - 2² = 863887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (863897) 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 7 ways as a sum of consecutive naturals, for example, 800 + ... + 1538.

It is an arithmetic number, because the mean of its divisors is an integer number (124320).

2⁸⁶³⁸⁹¹ is an apocalyptic number.

863891 is a deficient number, since it is larger than the sum of its proper divisors (130669).

863891 is a wasteful number, since it uses less digits than its factorization.

863891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913.

The product of its digits is 10368, while the sum is 35.

The square root of 863891 is about 929.4573685759. The cubic root of 863891 is about 95.2400577016.

The spelling of 863891 in words is "eight hundred sixty-three thousand, eight hundred ninety-one".