15609
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 23408
- Proper Divisor Sum (Aliquot Sum)
- 7799
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9240
- Möbius Function
- 0
- Radical
- 1419
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 146
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = (10n+1)*(10n+9).at n=12A001535
- Numbers k where cos(k) decreases monotonically to 0.at n=25A046957
- Numbers k where sin(k) increases monotonically to 1 (or cosec(k) decreases).at n=29A046959
- Monotonic ordering of nonnegative differences 5^i-4^j, for 40>= i>=0, j>=0.at n=26A192162
- The location of records in A210700.at n=26A210701
- Number of (n+1)X(n+1) -6..6 symmetric matrices with every 2X2 subblock having sum zero and one or three distinct values.at n=8A211255
- Number of 0..n arrays of length 6 with each element differing from at least one neighbor by 1 or less, starting with 0.at n=27A221685
- Number of partitions of 5n into exactly 4 parts.at n=26A256327
- Number of partitions of 3n into at most 4 parts.at n=42A256524
- a(n) = A261234(n) - A261237(n).at n=11A261236
- Expansion of Product_{k>=1} 1/((1 - x^prime(k))*(1 - x^(prime(k)^2))*(1 - x^(prime(k)^3))).at n=58A280715
- a(n) = 123*2^n - 135.at n=6A304831
- Numbers k such that 465*2^k+1 is prime.at n=30A318193