12449
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12720
- Proper Divisor Sum (Aliquot Sum)
- 271
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12180
- Möbius Function
- 1
- Radical
- 12449
- 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
- 156
- 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
- The game of Mousetrap with n cards: the number of permutations of n cards in which 2 is the only hit.at n=7A002469
- Triangle read by rows of numbers of permutations eliminating just card k out of n in game of Mousetrap.at n=37A028306
- Composite numbers such that all divisors >1 have the same number of 1's in binary representation.at n=30A089042
- a(n) = 10*a(n-1) - 17*a(n-2) for n > 1; a(0) = 1, a(1) = 21.at n=4A164606
- a(j) = maximum value of n for each distinct increasing value of (Sum of the quadratic non-residues of prime(n) - Sum of the quadratic residues of prime(n)) / prime(n) for each j.at n=16A166263
- n-th prime*8-7 is the square of a prime.at n=42A169583
- Numbers that are the product of two distinct primes a and b, such that a^3+b^3 is the average of a twin prime pair.at n=37A176876
- a(n) is the smallest multiple of n such that the sum of the square of the decimal digits of a(n) is divisible by n.at n=58A191872
- Number of terms of 2^j + 3^k <= 10^n.at n=41A219835
- The 180-degree spoke (or ray) of a hexagonal spiral of Ulam.at n=32A244806
- Numbers whose binary representation traces a non-selfcrossing circuit in the honeycomb lattice when each one of its bits, from the most significant to the least significant, is interpreted as a direction to proceed at each vertex.at n=50A255561
- Number of partitions p of n that contain a proper partition of the number of parts of p.at n=34A277753
- Partial sums of A080670.at n=53A287881
- Row sums of A291904.at n=50A291905
- Numbers whose sum of even digits and sum of odd digits are equal and whose digits are in nondecreasing order.at n=34A340125
- Number of face-connected components of tetragonal disphenoidal cells in the tetragonal disphenoidal honeycomb up to translation, rotation, and reflection.at n=9A385024
- Numbers that can be written in exactly two different ways as s_1^x_1 + ... + s_t^x_t, with 1 < s_1 < ... < s_t and {s_1,..., s_t} = {x_1,..., x_t} for some t > 0.at n=32A386966
- Numbers that can be written in exactly two different ways in the form described by A387302.at n=5A387898