7778
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11670
- Proper Divisor Sum (Aliquot Sum)
- 3892
- 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
- 3888
- Möbius Function
- 1
- Radical
- 7778
- 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
- 39
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers that are the sum of 3 positive 5th powers.at n=34A003348
- Number of rhyme schemes (see reference for precise definition).at n=7A005002
- a(n) = 6*n^2 + 2 for n > 0, a(0)=1.at n=36A005897
- a(0) = 1, a(n) = 24*n^2 + 2 for n>0.at n=18A010014
- Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for zeolite AEL = AlPO4-11 [Al20P20O80] starting with a T3 atom.at n=5A018944
- Pair up the numbers.at n=38A030655
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 88.at n=1A031586
- Gaps of 6 in sequence A038593 (lower terms).at n=2A038651
- Numbers ending with '8' that are the difference of two positive cubes.at n=29A038863
- Numbers having four 0's in base 6.at n=6A043372
- Numbers having three 7's in base 10.at n=28A043519
- a(2n) = concatenation of 4n+1 and 4n+2, a(2n+1) = concatenation of the two most nearly equal numbers whose product is a(2n).at n=38A068517
- Partition the concatenation 1234567...of natural numbers into successive strings which are even, all different and > 2. (0 never taken as the most significant digit.)at n=48A077295
- Nontrivial slowest increasing sequence whose succession of digits is that of the nonnegative integers.at n=39A098080
- Near-repdigit semiprimes with 7 as repeated digit.at n=18A105988
- a(n) = (A114043(n) - 1)/2.at n=14A115005
- The (1,4)-entry in the 4 X 4 matrix M^n, where M={{3, 2, 1, 1}, {2, 1, 1, 0}, {1, 1, 0, 0}, {1, 0, 0, 0}} (n>=0).at n=7A123942
- Number of partitions of n into "number of partitions of n into partition numbers" numbers.at n=43A130898
- 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), (-1, 0, 1), (1, 0, -1), (1, 1, 0)}.at n=8A149155
- 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, 0, 1), (0, 0, 1), (0, 1, -1), (1, -1, 0), (1, 0, 1)}.at n=7A150489