12357
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 17862
- Proper Divisor Sum (Aliquot Sum)
- 5505
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8232
- Möbius Function
- 0
- Radical
- 4119
- Omega Function (Ω)
- 3
- 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
- 37
- 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
- Lucky numbers with size of gaps equal to 20 (upper terms).at n=24A031903
- If n is composite replace n with the concatenation of its nontrivial divisors [ A037279 ] then divide out any factors of 2.at n=27A037280
- Numbers k such that 2*5^k + 1 is prime.at n=12A058934
- a(1) = 9, a(n) = concatenation of two closest factors of a(n-1) whose product equals a(n-1) or if a(n-1) is a prime then the concatenation of 1 and a(n-1).at n=5A063423
- a(n) = Sum_{k=0..floor(n/4)} C(n-2*k,2*k)*2^k.at n=18A098575
- Expansion of (1-x-2*x^2)/(1-2*x-3*x^2-4*x^3+4*x^4).at n=9A108480
- Concatenation of first n partition numbers of positive integers.at n=4A134802
- Sum of primes between consecutive positive cubes.at n=6A158528
- Concatenation of the first n elements of A008578.at n=4A159900
- Smallest number m such that exactly n odd numbers can be seen as proper subsequences of m in decimal representation.at n=28A164766
- Number of ways to place 4 nonattacking knights on an n X n toroidal board.at n=5A172531
- Number of (3+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=10A250758
- Integers m such that A006218(m) is triangular.at n=47A263457
- Number T(n,k) of defective parking functions of length n and defect k; triangle T(n,k), n>=0, 0<=k<=max(0,n-1), read by rows.at n=34A264902
- The Pnictogen sequence: a(n) = A018227(n)-3.at n=38A271995
- Number of integers in n-th generation of tree T(-3/4) defined in Comments.at n=42A274151
- Number of defective parking functions of length n and defect five.at n=2A291131
- Smallest n-digit decimal string that contains each of the first A294267(n) primes as a subsequence.at n=4A294268
- a(n) is the ending digit of a prime number occurring most up to the n-th prime. If a tie exists, then the digits are concatenated in ascending order.at n=4A301339
- Expansion of Product_{k>=1} (1 + x^k)^(k*A000010(k)), where A000010 is the Euler totient function.at n=13A301986