5221
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 5472
- Proper Divisor Sum (Aliquot Sum)
- 251
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4972
- Möbius Function
- 1
- Radical
- 5221
- Omega Function (Ω)
- 2
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 54
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2.at n=46A000566
- Running time of Takeuchi function.at n=7A000651
- a(n) = n^2 written backwards.at n=34A002942
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=29A003154
- Triangular numbers written backwards.at n=49A004158
- Odd heptagonal numbers (A000566).at n=23A014637
- Numbers k such that the continued fraction for sqrt(k) has period 92.at n=7A020431
- Arrange digits of squares in descending order.at n=35A028908
- Numbers k such that k^2 is palindromic in base 4.at n=20A029986
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 42 ones.at n=19A031810
- Numbers k such that 63*2^k+1 is prime.at n=38A032381
- Number of partitions of n into parts not of form 4k+2, 20k, 20k+9 or 20k-9. Also number of partitions in which no odd part is repeated, with at most 4 parts of size less than or equal to 2 and where differences between parts at distance 4 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=43A036028
- Numerators of continued fraction convergents to sqrt(880).at n=4A042700
- a(n) = 4*n^2 - 7*n + 4.at n=36A054567
- Least nontrivial multiple of the n-th prime beginning with 5.at n=48A078289
- Positions of A080313 in A014486.at n=10A080312
- n^2 read backwards, for n = 51, 50, 49, ..., 1.at n=16A080334
- a(n) = floor(e*(n+3)!) - (n+3)*(n+2)*(n+1)*n*floor(e*(n-1)!).at n=14A080770
- Composite numbers k such that the continued fraction for k/m contains no 2 for any 1 <= m <= k.at n=18A082409
- a(n) = A083960(n)/A004151(n).at n=18A083961