6456
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 16200
- Proper Divisor Sum (Aliquot Sum)
- 9744
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2144
- Möbius Function
- 0
- Radical
- 1614
- Omega Function (Ω)
- 5
- 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
- 75
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers n such that prime(n) mod n <= 10.at n=44A022465
- Numbers k such that prime(k) == 7 (mod k).at n=8A023149
- McKay-Thompson series of class 42b for Monster.at n=45A058676
- Numbers k that divide the average of prime(k-1) and prime(k).at n=6A066826
- Numbers k such that the digits of the k-th prime begin with k.at n=1A067928
- Numbers n such that, as strings, n is a substring of prime(n).at n=2A068575
- Let p and q be two prime numbers, not necessarily consecutive, such that q - p = 2n; a(n) is the number of distinct partitions of 2n into even numbers so that each partition corresponds to a consecutive prime difference pattern (k-tuple) and p<=A000230(n). Multiple occurrences of a partition are not counted.at n=48A079024
- n times the coefficient of x^n in log[1 + sum(k>=0, x^2^k)].at n=50A092462
- Number of solutions to x*frac[p(x)/x]<=Log[n] or A004648(n)<=Log[n].at n=20A099641
- Structured heptagonal diamond numbers (vertex structure 5).at n=15A100179
- Indices of primes in sequence defined by A(0) = 19, A(n) = 10*A(n-1) - 21 for n > 0.at n=14A102025
- Triangle read by rows: T(n,k) (0<=k<=n) is the number of Schroeder paths of length 2n, having k (1,0)-steps on the lines y=0 and y=1 (a Schroeder path of length 2n is a path from (0,0) to (2n,0), consisting of steps U=(1,1), D=(1,-1) and H=(2,0) and never going below the x-axis).at n=39A110189
- Numbers k such that k^2 + 11 and k^2 + 13 are primes.at n=27A113537
- Integers k such that 10^k+93 is a prime number.at n=13A135112
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 0), (-1, 1, 0), (1, 0, 1), (1, 1, 0)}.at n=7A150385
- a(n) = a(n-1) + a(n-2) - a(n-4) starting a(0)=0, a(1)=1, a(2)=a(3)=3.at n=28A168637
- a(n) = number of 7-digit primes with digit sum n, where n runs through the non-multiples of 3 in the range [2..62].at n=10A178876
- Where zeros occur in the 1-0 race in the binary expansion of Pi-3; that is, n such that A174832(n) = 0.at n=13A178980
- G.f. satisfies: A(x) = Product_{n>=1} (1 + x^n*A(x)^2)/(1 - x^n*A(x)^2).at n=5A192621
- Values of the difference d for 5 primes in geometric-arithmetic progression with the minimal sequence {5*5^j + j*d}, j = 0 to 4.at n=39A209204