7771
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
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8200
- Proper Divisor Sum (Aliquot Sum)
- 429
- 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
- 7344
- Möbius Function
- 1
- Radical
- 7771
- 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
- 114
- 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
- Number of free nonplanar polyenoids with n nodes and symmetry point group C_s.at n=6A000948
- G.f.: (1 + x^3 + x^4 + ... + x^12 + x^15)/Product_{i=1..10} (1 - x^i).at n=27A003403
- Numbers k such that the continued fraction for sqrt(k) has period 90.at n=13A020429
- a(n) = 6^n - n.at n=5A024063
- 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 87.at n=21A031585
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 44 ones.at n=26A031812
- Number of partitions of n into parts not of the form 15k, 15k+4 or 15k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 6 are greater than 1.at n=35A035958
- Numbers having four 5's in base 6.at n=21A043392
- Numbers having three 7's in base 10.at n=22A043519
- a(n) = (2*n-1)*(n^2 -n +6)/6.at n=28A049480
- a(n) = n*(n^2 - 6*n + 11)/6.at n=38A050407
- 13-gonal (or tridecagonal) numbers: a(n) = n*(11*n - 9)/2.at n=38A051865
- Triangle read by rows in which the n-th row contains n distinct numbers whose sum is n^n. The numbers are terms of an arithmetic progression with a common difference 1 or 2 respectively accordingly as n is odd or even.at n=15A080524
- First column of triangle in A080524.at n=5A080525
- a(n+3) = 2*a(n+2) + 3*(n+1) - a(n).at n=8A095310
- Number of different partitions of the set {1, 2, ..., n} into an odd number of blocks such that each block contains at least 2 elements.at n=9A097762
- a(n) = number of distinct values of Product_{i=1..r} x_i!*i!^x_i, where (x_1, ..., x_r) is an r-tuple of nonnegative integers with Sum_{i=1..r} i*x_i = n.at n=41A102465
- Minimal peaks in digital expansions of Pi: positions of peaks equal to 1.at n=9A105275
- Near-repdigit semiprimes with 7 as repeated digit.at n=16A105988
- Minimum over all permutations b of 1..n of sum b(i)*b^{-1}(i).at n=34A118375