812866 has 16 divisors (see below), whose sum is σ = 1306368. Its totient is φ = 378400.

The previous prime is 812857. The next prime is 812869. The reversal of 812866 is 668218.

It is a super-2 number, since 2×812866² = 1321502267912, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1671 + ... + 2101.

It is an arithmetic number, because the mean of its divisors is an integer number (81648).

2⁸¹²⁸⁶⁶ is an apocalyptic number.

812866 is a deficient number, since it is larger than the sum of its proper divisors (493502).

812866 is a wasteful number, since it uses less digits than its factorization.

812866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497.

The product of its digits is 4608, while the sum is 31.

The square root of 812866 is about 901.5908162798. The cubic root of 812866 is about 93.3267880898.

The spelling of 812866 in words is "eight hundred twelve thousand, eight hundred sixty-six".