4278
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 9216
- Proper Divisor Sum (Aliquot Sum)
- 4938
- 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
- 1320
- Möbius Function
- 1
- Radical
- 4278
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- yes
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 77
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Number of simple connected regular bipartite graphs with 2n nodes.at n=9A008323
- Second hexagonal numbers: a(n) = n*(2*n + 1).at n=46A014105
- Even triangular numbers.at n=46A014494
- Binomial coefficients C(n,91).at n=2A017755
- Binomial coefficients C(93,n).at n=2A017809
- Powers of cube root of 23 rounded down.at n=8A018042
- Powers of cube root of 23 rounded to nearest integer.at n=8A018043
- Smallest triangular number that begins with n.at n=41A018855
- a(n) = 2*n*(4*n + 1).at n=23A033585
- Number of positive integers <= 2^n of form 6 x^2 + 9 y^2.at n=16A054184
- Lesser members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).at n=19A054573
- Squarefree triangular numbers.at n=49A061304
- a(n) = 25*n*(n + 1)/2 + 3.at n=18A061793
- 3 times pentagonal numbers: 3*n*(3*n-1)/2.at n=31A062741
- Triangular numbers with sum of digits = 21.at n=4A068131
- Triangular numbers of the form 6*k.at n=30A069497
- Triangular numbers in A062918.at n=12A069792
- Abundant triangular numbers.at n=33A074315
- Friendly numbers (see A074902) such that sigma(n) is not friendly.at n=19A074873
- Trajectory of n under the Reverse and Add! operation carried out in base 4 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=11A075421