16201
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
- 4
- Divisor Sum
- 17172
- Proper Divisor Sum (Aliquot Sum)
- 971
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15232
- Möbius Function
- 1
- Radical
- 16201
- 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
- 66
- 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
- a(n) = 10*n^2 + 5*n + 1.at n=40A080860
- a(n) = 12*a(n-2) - 25*a(n-4) with initial terms 1,6,17,47.at n=8A083334
- Middle term of a triple of consecutive numbers which are sums of two squares.at n=9A096129
- a(n) = number of ks that make primorial P(n)/A019565(k)-A019565(k) prime.at n=16A103788
- Negative numbers written in a bits-of-Pi/primorial base system.at n=18A109839
- Semiprimes of the form 2*n + 1, where n is a square.at n=40A111351
- Integers k such that 10^k+37 is a prime number.at n=24A135109
- Numbers k that divide the sum of the digits of k^k in base 2.at n=6A138572
- a(n) = 18*n^2 + 1.at n=29A157889
- a(n) = 50*n^2 + 1.at n=17A157916
- a(n) = 900*n + 1.at n=17A158407
- a(n) = 72*n^2 + 1.at n=15A158740
- a(n) = n^3 + (1-n)^2.at n=25A168297
- a(n) is the smallest term m in A173978 for which A020639(2m-3) = prime(n), n > 1.at n=39A173980
- A symmetrical triangle sequence: t(n,m)=n!*Eulerian[n + 1, m]^2 - n! + 1.at n=11A174692
- A symmetrical triangle sequence: t(n,m)=n!*Eulerian[n + 1, m]^2 - n! + 1.at n=13A174692
- a(n) = Sum_{k=0..n} Stirling2(n,k)*Stirling2(n+1,k+1)*k!.at n=5A192557
- Smallest number k such that sopf(k)/digsum(k) = prime(n) where sopf(k) is the sum of the distinct primes dividing k and digsum(k) the sum of digits of k.at n=24A241049
- Rectangular array A read by upward antidiagonals: A(n,m) is the number of total difunctional (regular) binary relations between an n-element set and an m-element set.at n=40A265706
- Rectangular array A read by upward antidiagonals: A(n,m) is the number of surjective difunctional (regular) binary relations between an n-element set and an m-element set.at n=40A265707