Number 15
The number 15 is the 5th triangular number. It has 4 divisors and a digital root of 6. Explore its full properties below, or find words and phrases with a gematria value of 15.
15
Divisors: 4
1, 3, 5, 15
Sum: 24
Prev Triangular: 10
5th Triangular Number
Next Triangular: 21
Mathematical Properties
Golden Number987
Reduced Digit Sum6
Magic Constant1,695
Digital Root6
Octal13(17)
Duodecimal17(13)
Hexadecimal21(f)
Binary1111
15th Values
Prime47
Triangular120
Square225
Star1,261
Pentagonal330
Cube3,375
Tetrahedral680
Square Pyramidal1,240
Fibonacci610
Harshad24
Happy Number103