 |
|
| ||||||||||||||||||||||||||
|
|
| ||||||||||||||||||||||||||
|
|
|
|
One hundred seventy a sphenic number. It is the smallest n for which φ(n) and σ(n) are both square. But 170 is never a solution for φ(x), making it a nontotient. Nor is it ever a solution to x - φ(x), making it a noncototient.
One hundred seventy is also
171 = 3^2 19, triangular number, Harshad number
172 = 2^2 43, noncototient
173 = prime number, sum of three consecutive primes (53 + 59 + 61)
174 = 2 3 29, sphenic number, nontotient
175 = 5^2 7
176 = 2^4 11, pentagonal number, octagonal number, octagonal pentagonal number, self number
177 = 3 59
178 = 2 89
179 = prime number
|
||||
| View Live Article | This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License | |
||
