861806 has 16 divisors (see below), whose sum is σ = 1444608. Its totient is φ = 382200.

The previous prime is 861803. The next prime is 861823. The reversal of 861806 is 608168.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861806.

It is not an unprimeable number, because it can be changed into a prime (861803) 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, 491 + ... + 1401.

It is an arithmetic number, because the mean of its divisors is an integer number (90288).

2⁸⁶¹⁸⁰⁶ is an apocalyptic number.

861806 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

861806 is a deficient number, since it is larger than the sum of its proper divisors (582802).

861806 is a wasteful number, since it uses less digits than its factorization.

861806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 861806 is about 928.3350688194. The cubic root of 861806 is about 95.1633753853.

The spelling of 861806 in words is "eight hundred sixty-one thousand, eight hundred six".