11026
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17100
- Proper Divisor Sum (Aliquot Sum)
- 6074
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5328
- Möbius Function
- -1
- Radical
- 11026
- 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
- yes
- 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
- 99
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = p*(p-1)/2 for p = prime(n).at n=34A008837
- Pisot sequence T(4,6), a(n) = floor(a(n-1)^2/a(n-2)).at n=29A020747
- Pisot sequence T(6,9), a(n) = floor(a(n-1)^2/a(n-2)).at n=28A020751
- a(n) = n*(n^2 + 12*n - 25)/6.at n=37A026057
- a(n) = 2*n*(4*n + 1).at n=37A033585
- Numbers having four 1's in base 9.at n=30A043460
- a(n) = A047881(n) / 2.at n=38A047882
- Numbers k such that k | 10^k + 9^k + 8^k + 7^k.at n=24A057214
- Triangular numbers whose reverse is prime.at n=9A066751
- Triangular numbers with sum of digits = 10.at n=21A068129
- Triangular numbers with arithmetic mean of digits = integer (sum of digits = A multiple of the number of digits).at n=44A069712
- Triangular number x such that x + reverse of x is a prime.at n=3A072387
- Triangular numbers which are the sum of two squares.at n=25A073613
- Triangular numbers that are 3-almost primes.at n=44A075875
- a(n) = (25*n^2 - 15*n + 2)/2.at n=30A080857
- Triangular numbers obtained as a concatenation of successive terms of A081847.at n=16A082235
- Sort the digits of these triangular numbers into descending order and drop zeros to get primes.at n=18A082923
- a(n) = smallest k where (10^k+1)=0 mod prime(n)^2, or 0 if no such k exists.at n=34A086981
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=3A103950
- Triangular numbers that are sums of two consecutive primes.at n=21A111163