11521
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11844
- Proper Divisor Sum (Aliquot Sum)
- 323
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11200
- Möbius Function
- 1
- Radical
- 11521
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 174
- 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
- Number of partitions into non-integral powers.at n=40A000327
- Centered octahedral numbers (crystal ball sequence for cubic lattice).at n=20A001845
- a(n) = C(n,1) + C(n,2) + C(n,3), or n*(n^2 + 5)/6.at n=41A004006
- Pseudoprimes to base 7.at n=20A005938
- Expansion of 1/(1-x^4-x^5-x^6).at n=49A017828
- Pseudoprimes to base 40.at n=36A020168
- Pseudoprimes to base 60.at n=26A020188
- Pseudoprimes to base 90.at n=20A020218
- Strong pseudoprimes to base 60.at n=12A020286
- Strong pseudoprimes to base 62.at n=18A020288
- Strong pseudoprimes to base 67.at n=9A020293
- Strong pseudoprimes to base 89.at n=15A020315
- Strong pseudoprimes to base 93.at n=16A020319
- Numbers k such that the continued fraction for sqrt(k) has period 75.at n=7A020414
- Positive numbers for which the sum of digits equals the product of digits.at n=37A034710
- a(n) = T(4,n), array T given by A048472.at n=9A048476
- Array T read by diagonals, n-th difference of (T(k,n),T(k,n-1),...,T(k,0)) is (k+n)^2, for n=1,2,3,...; k=0,1,2,...at n=45A048505
- a(n) = T(0,n), array T given by A048505.at n=9A048506
- 16-gonal (or hexadecagonal) numbers: a(n) = n*(7*n-6).at n=41A051868
- Sum of a(n) terms of 1/k^(3/4) first exceeds n.at n=38A056179