13689
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 15
- Divisor Sum
- 22143
- Proper Divisor Sum (Aliquot Sum)
- 8454
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8424
- Möbius Function
- 0
- Radical
- 39
- Omega Function (Ω)
- 6
- 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
- yes
- 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
- 151
- Smith Number
- no
- Vampire Number
- 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
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Squares of odd pentagonal numbers.at n=4A014769
- a(n) = (3*n)^2.at n=39A016766
- a(n) = (4*n + 1)^2.at n=29A016814
- a(n) = (5*n + 2)^2.at n=23A016874
- a(n) = (6*n+3)^2.at n=19A016946
- a(n) = (7*n + 5)^2.at n=16A017042
- a(n) = (8*n + 5)^2.at n=14A017126
- a(n) = (9*n)^2.at n=13A017162
- a(n) = (10*n + 7)^2.at n=11A017354
- a(n) = (11*n + 7)^2.at n=10A017474
- a(n) = (12*n + 9)^2.at n=9A017630
- [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 2 mod 3}.at n=14A024402
- Squares with digits in nondecreasing order.at n=22A028820
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 13 (most significant digit on left).at n=37A029458
- Numbers with 15 divisors.at n=16A030633
- Arrange digits of cubes in ascending order.at n=27A032553
- Squares that remain a square if a suitably chosen digit is dropped.at n=42A034377
- Squares and omitting some digit gives another number in this list.at n=23A034378
- Numbers k that divide 7^k + 2^k.at n=31A045580
- Numbers k that divide 7^k + 5^k.at n=26A045596