7201
domain: N
Properties
Digital Properties
- Digit Count
- 4
- 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
- 7600
- Proper Divisor Sum (Aliquot Sum)
- 399
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6804
- Möbius Function
- 1
- Radical
- 7201
- 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
- 163
- 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
- Numbers that are the sum of 8 positive 7th powers.at n=29A003375
- Pseudoprimes to base 40.at n=27A020168
- Pseudoprimes to base 51.at n=28A020179
- Pseudoprimes to base 52.at n=27A020180
- Pseudoprimes to base 84.at n=22A020212
- Strong pseudoprimes to base 40.at n=11A020266
- Strong pseudoprimes to base 52.at n=7A020278
- Number of singular 2 X 2 matrices over Z(n) (i.e., with determinant = 0).at n=18A020478
- Number of noninvertible 2 X 2 matrices over Z/nZ (determinant is a divisor of 0).at n=17A020479
- Least m such that if r and s in {1/4, 1/8, 1/12, ..., 1/4n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=32A024839
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 60 ones.at n=9A031828
- Number of partitions of n with equal nonzero number of parts congruent to each of 1 and 2 (mod 5).at n=45A035566
- Number of partitions satisfying cn(0,5) + cn(1,5) < cn(2,5) + cn(3,5) and cn(0,5) + cn(4,5) < cn(2,5) + cn(3,5).at n=36A039884
- Number of "polyhes" of order n: a polyhe of order n is obtained by taking a polyhex made of n hexagons (A000228); cutting each of the n hexagons along a diameter and throwing away half that hexagon, in such a way that the remaining figure (made of n half-hexagons) is connected.at n=6A057712
- Numbers k such that A064604(k) is divisible by k.at n=9A064607
- Composite numbers m such that phi(m)*sigma(m) is divisible by m-1.at n=19A065149
- Numbers k such that Euler phi(k) / Carmichael lambda(k) = 18.at n=36A066697
- Centered 24-gonal numbers.at n=24A069190
- Diagonal in array of n-gonal numbers A081422.at n=18A081437
- Third row of Pascal-(1,3,1) array A081578.at n=30A081585