## Wednesday, July 21, 2010

### 773

773 is a prime number.

773 has a representation as a sum of two squares: 773 = 172 + 222.

773 is the hypotenuse of a primitive Pythagorean triple: 7732 = 1952 + 7482.

773 is the largest three-digit unholey prime; its digits have no holes.

773 is the smallest prime such that adding a preceding or trailing digit will always result in a composite if we omit the case where the leading digit is zero.

773 is a telephone area code for Chicago.

#### 1 comment:

Anonymous said...

Other representations of number 773:
773=3^6+44
773=7^2+18^2+20^2=8^2+15^2+22^2=10^2+12^2+23^2
773=7^2+12^2+16^2+18^2
773=5^3+6^3+6^3+6^3
773 is a prime veryprime weak, see A050264
Tetranacci 773 is a number, see A000078
773 can be represented as the sum of a square and a cousin
773=2^2+769=4^2+757=8^2+709=10^2+673 finite representations
773 can be represented as the difference of a square and a cousin
773=30^2-127=32^2-251=34^2-383=40^2-827 infinite representations
Also can be represented as a sum or difference of power plus a prime number
773=4^3+709=6^3+557
773=2^4+757
773=2^6+709
773=30^3-26227
773=34^4-1335563
Rafael Parra de Barcelona