16130
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 29052
- Proper Divisor Sum (Aliquot Sum)
- 12922
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6448
- Möbius Function
- -1
- Radical
- 16130
- 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
- 71
- 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(0) = 1, a(n) = 28*n^2 + 2 for n>0.at n=24A010018
- Numbers n such that n through n+5 have the same number of distinct prime factors.at n=16A045934
- a(n) = ceiling(a(n-1)/2) + a(n-2) with a(0)=0 and a(1)=1.at n=39A064651
- a(n) = prime(n)^2 + 1.at n=30A066872
- Prime(prime(n))^2+1.at n=10A092774
- Triangle, read by rows, where T(n,k) = Sum_{i=k..n-1} T(n-1,i)*T(i+1,k+1) for n>k with T(n,n) = n+1 for n>=0.at n=41A152541
- Partial sums of Wagstaff numbers A000978.at n=23A172296
- Number of strings of numbers x(i=1..n) in 0..2 with sum i*x(i) equal to n*2.at n=23A184696
- Number of bitstrings of length n which (if having two or more runs) the last two runs have different lengths.at n=13A208900
- Expansion of q^(-1/3) * a(q)^2 * c(q) / 3 in powers of q where a(), c() are cubic AGM theta functions.at n=42A231947
- Numbers k of the form p^2 + 1 (for prime p) where k^2 + 1 is also prime.at n=5A235053
- Smallest even k such that lpf(k-1) = prime(n), while lpf(k-3) > prime(n), where lpf=least prime factor (A020639).at n=29A242489
- Smallest even k such that lpf(k-3) > lpf(k-1) >= prime(n), where lpf=least prime factor (A020639).at n=28A242719
- Smallest even k such that lpf(k-3) > lpf(k-1) >= prime(n), where lpf=least prime factor (A020639).at n=29A242719
- The smallest numbers of every class in a classification of positive numbers (see comment).at n=32A247395
- Number of compositions of n into parts 1, 6, and 7.at n=34A259278
- Number of (i,j,k) in {1,2,...,n}^3 such that gcd(n,i) = gcd(n,j) = gcd(n,k).at n=49A338997
- First occurrence of difference n between two consecutive terms of A000404. a(n) gives the upper term. The lower term is A355237.at n=20A355238
- a(n) = number of pairs (p,q) of partitions of n such that d(p,q) > o(p,q), where d and o are distance functions; see Comments.at n=23A368566