16770
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 44352
- Proper Divisor Sum (Aliquot Sum)
- 27582
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4032
- Möbius Function
- -1
- Radical
- 16770
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 5
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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 66
- Smith Number
- yes
- 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
- Number of equivalence classes of binary sequences of period n.at n=23A002729
- Numbers that are the sum of 6 positive 7th powers.at n=31A003373
- a(n) = n*(n^2 + 12*n - 25)/6.at n=43A026057
- Hexagonal matchstick numbers: a(n) = 3*n*(3*n+1).at n=43A045945
- Numbers k that, when expressed in base 5 and then interpreted in base 8, give a multiple of k.at n=35A062930
- Numbers n such that sigma(n)/phi(n) is prime.at n=30A067780
- Product of the distinct primes dividing the product of composite numbers between consecutive primes.at n=30A076978
- Squarefree balanced numbers (i.e., squarefree members of A020492).at n=33A078557
- Product of all distinct prime factors of all composite numbers between n-th prime and next prime.at n=29A079615
- Squarefree oblong (pronic) numbers having an odd number of prime factors.at n=19A098827
- a(1) = 1+2-3 = 0, a(2) = 4+5+6-7 = 8, a(3) = 8+9+10+11-12 = 26, a(4) = 13+14+15+16+17-18 = 57, ...at n=30A111694
- Numbers such that sigma(n)^2 is divisible by UnitarySigma(n)*UnitaryPhi(n).at n=42A121556
- Numbers such that Sigma(m)*UnitarySigma(m)= k*UnitaryPhi(m)^2, for some integer k.at n=38A122839
- Numbers m such that UnitarySigma(m)^2 = k*Sigma(m)*UnitaryPhi(m), for some integer k.at n=38A123041
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 0), (0, -1, 1), (1, 1, -1), (1, 1, 0)}.at n=9A148819
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 0), (0, -1, 1), (0, 1, 1), (1, 0, -1)}.at n=9A148840
- a(n) = (4*n+1)*(4*n+2) = (4*n+2)!/(4*n)!.at n=32A157870
- Number of nXnXn triangular 1..3 arrays with all 1s connected, all 2s connected, all 3s connected, 1 at the top vertex, 2 at the lower left, and 3 at the lower right, and no value having more than 4 identical values adjacent.at n=4A164746
- Numbers n such that sigma(n) = 11*phi(n) (where sigma=A000203, phi=A000010).at n=1A171257
- a(n) = (7*n + 3)*(7*n + 4).at n=18A177071