# 206 (number)

Short description: Natural number
 ← 205 206 207 →
Cardinaltwo hundred six
Ordinal206th
(two hundred sixth)
Factorization2 × 103
Divisors1, 2, 103, 206
Greek numeralΣϚ´
Roman numeralCCVI
Binary110011102
Ternary211223
Quaternary30324
Quinary13115
Senary5426
Octal3168
Duodecimal15212
VigesimalA620
Base 365Q36

206 (two hundred [and] six) is the natural number following 205 and preceding 207.

## In mathematics

206 is both a nontotient and a noncototient.[1] 206 is an untouchable number.[2] It is the lowest positive integer (when written in English as "two hundred and six") to employ all of the vowels once only, not including Y. The other numbers sharing this property are 230, 250, 260, 602, 640, 5000, 8000, 9000, 26,000, 80,000 and 90,000.[3] 206 and 207 form the second pair of consecutive numbers (after 14 and 15) whose sums of divisors are equal.[4] There are exactly 206 different linear forests on five labeled nodes,[5] and exactly 206 regular semigroups of order four up to isomorphism and anti-isomorphism.[6]

## In science

There are 206 bones in the typical adult human body.[7]