1

domain: N

Properties

Digital Properties

Digit Count
1
Digit Sum
1
Digital Root
1
Palindromic Number
yes
Repdigit
yes
Automorphic
yes
Kaprekar Number
yes
Multiplicative Persistence
0

Divisibility

Divisor Count
1
Divisor Sum
1
Proper Divisor Sum (Aliquot Sum)
0
Abundant Number
no
Perfect Number
no
Deficient Number
yes
Highly Composite
yes
Weird Number
no
Untouchable Number
no
Primitive Abundant
no

Derived Values

Euler's Totient
1
Möbius Function
1
Radical
1
Omega Function (Ω)
0
Little Omega Function (ω)
0

Special

Factorial
yes
Catalan Number
yes
Bell Number
yes
Motzkin Number
yes
Primorial
yes

Figurate Numbers

Fibonacci Number
yes
Triangular Number
yes
Perfect Square
yes
Perfect Cube
yes
Pentagonal Number
yes
Hexagonal Number
yes
Lucas Number
yes
Tetrahedral Number
yes
Pell Number
yes
Tribonacci Number
yes
Pronic Number
no

Recreational

Happy Number
yes
Harshad Number
yes
Narcissistic Number
yes
Collatz Steps
0
Smith Number
no

Classification

Natural
yes
Even
no
Odd
yes

Primality

Prime
no
Composite Number
no
Semiprime
no
Squarefree Number
yes
Prime Power
no
Twin Prime
no
Mersenne Prime
no
Sophie Germain Prime
no
Safe Prime
no
Powerful Number
yes
Achilles Number
yes
Perfect Power
no
Smooth Number
yes
Carmichael Number
no

Names

German
eins· ordinal: erste
English
one· ordinal: first
Spanish
uno· ordinal: primero
French
un· ordinal: premier
Italian
uno· ordinal: primo
Latin
unus· ordinal: primus
Portuguese
um· ordinal: primeiro

Appears in sequences