811866 has 16 divisors (see below), whose sum is σ = 1771488. Its totient is φ = 246000.

The previous prime is 811861. The next prime is 811871. The reversal of 811866 is 668118.

811866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (811861) and next prime (811871).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (811861) by changing a digit.

811866 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6085 + ... + 6216.

It is an arithmetic number, because the mean of its divisors is an integer number (110718).

2⁸¹¹⁸⁶⁶ is an apocalyptic number.

811866 is an abundant number, since it is smaller than the sum of its proper divisors (959622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811866 is a wasteful number, since it uses less digits than its factorization.

811866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12317.

The product of its digits is 2304, while the sum is 30.

The square root of 811866 is about 901.0360703102. The cubic root of 811866 is about 93.2885017117.

The spelling of 811866 in words is "eight hundred eleven thousand, eight hundred sixty-six".