Number 1
Representations of 1
Characteristics
Triangular
Pentagonal
Hexagonal
Heptagonal
Octogonal
Nonagonal
Decagonal
Square
Cubic
Fourth Power
Fifth Power
Difference of 2 squares
Palindromic
Harshad
Kaprekar
Mersenne
One O
Odd
Fibonacci
Ones-Zeroes
Unit
Deficient
Related primes
Number 1 prime
2