11155
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14112
- Proper Divisor Sum (Aliquot Sum)
- 2957
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8448
- Möbius Function
- -1
- Radical
- 11155
- 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
- 42
- 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
- Third differences of Bell numbers.at n=6A011966
- Aitken's array: triangle of numbers {a(n,k), n >= 0, 0 <= k <= n} read by rows, defined by a(0,0)=1, a(n,0) = a(n-1,n-1), a(n,k) = a(n,k-1) + a(n-1,k-1).at n=41A011971
- Sequence formed by reading rows of triangle defined in A011971.at n=33A011972
- Pseudoprimes to base 96.at n=35A020224
- Expansion of 1/((1-9*x)*(1-10*x)*(1-12*x)).at n=3A020983
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 22.at n=13A022186
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 22.at n=11A022186
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=34A024848
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 25 ones.at n=3A031793
- Numbers whose base-7 representation contains exactly four 4's.at n=11A043412
- a(n) = n^3 + n^2 + n + 1.at n=22A053698
- Numbers with all odd digits, in which each digit divides the number formed by the rest, i.e., the number obtained by just removing this digit.at n=41A061507
- Composite numbers k such that sigma(k)*(phi(k) + 2) is a square.at n=22A065655
- Group the natural numbers such that the n-th group sum is divisible by prime(n): (1, 2, 3), (4, 5), (6, 7, 8, 9), (10, 11), (12, 13, 14, 15, 16, 17, 18, 19, 20, 21), ... Sequence contains the sum of the terms in the n-th group.at n=24A086491
- Triangle read by rows: Aitken's array (A011971) but with a leading diagonal before it given by the Bell numbers (A000110), 1, 1, 2, 5, 15, 52, ...at n=51A095149
- Iccanobirt numbers (2 of 15): a(n) = a(n-1) + R(a(n-2)) + a(n-3), where R is the digit reversal function A004086.at n=15A102112
- Difference array of Bell numbers A000110 read by antidiagonals.at n=51A106436
- Mirror image of the Bell triangle A011971, which is also called the Pierce triangle or Aitken's array.at n=39A123346
- 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), (0, 1, -1), (1, -1, 0), (1, 0, 0)}.at n=10A148189
- Greatest number m such that the fractional part of (101/100)^A153669(n) <= 1/m.at n=8A153673