7663
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7840
- Proper Divisor Sum (Aliquot Sum)
- 177
- 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
- 7488
- Möbius Function
- 1
- Radical
- 7663
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 88
- 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 with exactly 7 1's in their ternary expansion.at n=25A023698
- Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 19 (most significant digit on right and removing all least significant zeros before concatenation).at n=20A029536
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.at n=16A031779
- a(n) = C(n+2,3) + 2*C(n,2) + 2*(n-2).at n=32A034857
- Composite numbers whose prime factors have no digits other than 7's and 9's.at n=11A036324
- Sums of 11 distinct powers of 2.at n=37A038462
- a(n) is the smallest composite number c such that A002110(n) + c is prime.at n=21A038771
- Numerators of continued fraction convergents to sqrt(749).at n=8A042442
- Semiprimes whose prime factors, when concatenated, yield a palindrome.at n=43A046451
- n-th 4k+1 prime times (n+1)st 4k+3 prime.at n=10A048628
- a(n) = Sum_{k=0,1,2,...,n-4,n-2,n-1} a(k); a(n-3) is not a summand, with a(0)=a(1)=a(2)=1.at n=16A049864
- Composite and every divisor (except 1) contains the digit 7.at n=41A062676
- Rounded volume of a regular dodecahedron with edge length n.at n=10A071401
- Nonsquares which are the product of two numbers with the same digits (leading zeros are forbidden).at n=34A072443
- Semiprimes whose prime factors are distinct and the reversal of one factor is equal to the other.at n=3A083815
- a(n) = prime(n)*prime(n+3).at n=21A090090
- Products of two primes that are not Chen primes.at n=19A115719
- Number of parts that are multiples of 3 in all partitions of n.at n=29A116635
- Triangle read by rows: T(n,k) is the number of binary sequences of length n containing k subsequences 0110 (n,k >= 0).at n=36A118890
- One-seventh of the difference of squares of legs of primitive Pythagorean triangles, neither of which is a multiple of 7.at n=32A127924