40

domain: N

Properties

Digital Properties

Digit Count
2
Digit Sum
4
Digital Root
4
Palindromic Number
no
Repdigit
no
Automorphic
no
Kaprekar Number
no
Multiplicative Persistence
1

Divisibility

Divisor Count
8
Divisor Sum
90
Proper Divisor Sum (Aliquot Sum)
50
Abundant Number
yes
Perfect Number
no
Deficient Number
no
Highly Composite
no
Weird Number
no
Untouchable Number
no
Primitive Abundant
no

Derived Values

Euler's Totient
16
Möbius Function
0
Radical
10
Omega Function (Ω)
4
Little Omega Function (ω)
2

Special

Factorial
no
Catalan Number
no
Bell Number
no
Motzkin Number
no
Primorial
no

Figurate Numbers

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

Recreational

Happy Number
no
Harshad Number
yes
Narcissistic Number
no
Collatz Steps
8
Smith Number
no

Classification

Natural
yes
Even
yes
Odd
no

Primality

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

Names

German
vierzig· ordinal: vierzigste
English
forty· ordinal: fortieth
Spanish
cuarenta· ordinal: 40º
French
quarante· ordinal: quarantième
Italian
quaranta· ordinal: 40º
Latin
quadraginta· ordinal: 40.
Portuguese
quarenta· ordinal: 40º

Appears in sequences