11911
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12232
- Proper Divisor Sum (Aliquot Sum)
- 321
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11592
- Möbius Function
- 1
- Radical
- 11911
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 125
- 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
- Partial sums of A027035.at n=9A027036
- Palindromic lucky numbers.at n=31A031161
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 35 ones.at n=1A031803
- Lucky numbers that are both palindromic and nonprime.at n=25A031880
- Numbers with multiplicative digital root value 9.at n=25A034056
- Palindromic Fibonacci-lucky numbers.at n=47A039674
- Base 10 palindromes that start with 1.at n=41A043036
- Numbers having four 1's in base 10.at n=28A043496
- Number of connected chordal graphs on n vertices.at n=8A048192
- Numbers where the difference of consecutive fifth powers is "close" to another fifth power: let m = k^5 - (k-1)^5; sequence lists the numbers k where m - floor(m^(1/5))^5 < floor(sqrt(k))^5.at n=4A053804
- Transform of A059502 applied to sequence 5,6,7,...at n=8A059508
- Numbers k such that z(k) = j(k), where z(k) = sopf(k - d(k)), j(k) = d(sopf(k) + k), sopf(k) = A008472(k) and d(k) = A000005(k).at n=19A063961
- Palindromes whose product of digits is a positive palindrome.at n=39A082207
- Palindromic time display in hours, minutes, seconds on a six spaced 24-hour digital clock, using hours 1-24.at n=19A082567
- a(n) is the odd-length palindrome whose digits up to the center are those of n and whose center digit is equal to the digital root of the product of the factorial of n and the reverse of n.at n=10A082941
- Palindromes such that the sum of the digits is prime.at n=44A083393
- a(n) = Sum_{i=1..n} 2^(b(i) - 1), where b(n) is the differences between consecutive primes.at n=45A086769
- a(1) = 2; then least palindrome greater than the previous term such that every partial concatenation is a prime.at n=10A088084
- Number of planar partitions of n with trace 4.at n=16A089351
- G.f.: Product_{k>0} (1+x^k)/((1-x^k)*(1+x^(3k))*(1+x^(5k))).at n=25A100823