7527
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
- 8
- Divisor Sum
- 10864
- Proper Divisor Sum (Aliquot Sum)
- 3337
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4608
- Möbius Function
- -1
- Radical
- 7527
- Omega Function (Ω)
- 3
- 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
- 150
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-5).at n=24A023435
- Numbers whose set of base-12 digits is {3,4}.at n=26A032836
- G.f.: 1 / Product_{k>=1} (1-x^k)^(k-1).at n=20A052847
- McKay-Thompson series of class 50a for Monster.at n=57A058703
- a(1) = 9; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=42A074345
- Positions of check bits in code in A075934.at n=39A075936
- Maximum number of nonempty subtrees of a binary tree with n leaves.at n=9A092781
- Least k such that the Collatz (3x+1) iteration starting with k has "dropping time" A122437(n).at n=46A122442
- a(n) = n*(n-1)*(n^3 + 21*n^2 - 4*n + 96)/120.at n=13A124161
- Maximum possible number of subtrees of an n-node unrooted tree in which each node has maximum degree three (equivalently, rooted binary trees in which some internal nodes may have only one child). A subtree is a nonempty contiguous set of nodes, not necessarily including all descendants of the root.at n=19A124454
- Numbers k such that k and k^2 use only the digits 2, 5, 6, 7 and 9.at n=18A137112
- Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 11011-01110-00100 pattern in any orientation.at n=10A147482
- a(n) = (5*n-7)*(n-1).at n=39A147874
- a(0)=1, a(1)=0, a(2)=2, a(3)=1, a(n)=a(n-2)+a(n-3)+a(n-4) for n>3.at n=25A167704
- Number of partitions of n such that smaller parts do not occur more frequently than greater parts.at n=49A171979
- a(n) = 4*n^2 + 3*n + 2.at n=43A185669
- Monotonic ordering of set S generated by these rules: if x and y are in S then 5xy-x-y is in S, and 1 is in S.at n=25A192528
- Number of order-preserving or order-reversing full contraction mappings (of an n-chain) with exactly 1 fixed point.at n=10A221880
- Conjectured irregular triangle (with some rows blank) of numbers k such that prime(n) is the largest prime factor of k^3 - 1.at n=54A223703
- Solutions to phi(n) = phi(sigma(n)) that are not given by Theorem 3 of Golomb's manuscript.at n=43A260021