11969
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 11970
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11968
- Möbius Function
- -1
- Radical
- 11969
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 50
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1435
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Centered 4-dimensional orthoplex numbers (crystal ball sequence for 4-dimensional cubic lattice).at n=11A001846
- Numbers k such that the continued fraction for sqrt(k) has period 91.at n=4A020430
- Smallest prime containing n-th square as substring.at n=14A029948
- Smallest prime with "n^2" as central digit(s).at n=14A038370
- Recursive prime generating sequence.at n=49A039726
- Smaller of twin primes whose middle term is a multiple of A002110(4)=210.at n=15A060230
- a(1) = 2; a(n) is the smallest prime > a(n-1) such that a(n) + a(n-1) is a square.at n=16A062064
- Partial sums of sequence (essentially A002378): 1, 2, 6, 12, 20, 30, 42, 56, 72, 90, ...at n=32A064999
- Smallest prime containing the n-th square in decimal notation.at n=13A065144
- Numbers which need ten 'Reverse and Add' steps to reach a palindrome.at n=35A065215
- a(n) is the unique positive integer m which has a self-conjugate partition whose parts are the first n primes.at n=40A067773
- Number of nodes in virtual, "optimal", chordal graphs of diameter 4 and degree n+1.at n=20A067956
- Base 4 expansion of 1/n has equal percentage of each digit 0,1,2,3.at n=17A074709
- Base 4 expansion of 1/n has equal percentage of each digit 0,1,2,3 (primitive values of n only).at n=15A074900
- Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=20A075585
- Smallest number that requires n steps to reach 0 when iterating the mapping k -> abs(reverse(lpd(k))-reverse(Lpf(k))). lpd(k) is the largest proper divisor and Lpf(k) is the largest prime factor of k.at n=15A076424
- Successive record-setters for tau(n+1)*tau(n-1)/tau(n)^2, where tau(n) is the number of divisors of n.at n=22A094342
- Nontrivial Delannoy numbers that are primes.at n=28A101167
- Primes of the form 128n+65.at n=24A105129
- Primes p such that p + 2 and p*(p + 2) + 2 are primes.at n=26A108013