206856 has 72 divisors (see below), whose sum is σ = 642330. Its totient is φ = 59904.

The previous prime is 206827. The next prime is 206879. The reversal of 206856 is 658602.

It can be written as a sum of positive squares in 3 ways, for example, as 133956 + 72900 = 366^2 + 270^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a plaindrome in base 14.

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12160 + ... + 12176.

2²⁰⁶⁸⁵⁶ is an apocalyptic number.

206856 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321165).

206856 is an abundant number, since it is smaller than the sum of its proper divisors (435474).

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

206856 is a wasteful number, since it uses less digits than its factorization.

206856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 206856 is about 454.8142477979. The cubic root of 206856 is about 59.1410967560.

The spelling of 206856 in words is "two hundred six thousand, eight hundred fifty-six".