811863 has 24 divisors (see below), whose sum is σ = 1314768. Its totient is φ = 497664.

The previous prime is 811861. The next prime is 811871. The reversal of 811863 is 368118.

It is not a de Polignac number, because 811863 - 2¹ = 811861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

811863 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811861) 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 23 ways as a sum of consecutive naturals, for example, 3031 + ... + 3287.

It is an arithmetic number, because the mean of its divisors is an integer number (54782).

2⁸¹¹⁸⁶³ is an apocalyptic number.

811863 is a deficient number, since it is larger than the sum of its proper divisors (502905).

811863 is a wasteful number, since it uses less digits than its factorization.

811863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285 (or 273 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 811863 is about 901.0344055584. The cubic root of 811863 is about 93.2883868053.

The spelling of 811863 in words is "eight hundred eleven thousand, eight hundred sixty-three".