7751
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8112
- Proper Divisor Sum (Aliquot Sum)
- 361
- 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
- 7392
- Möbius Function
- 1
- Radical
- 7751
- 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
- 176
- 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
- a(n) = 6^n - n^2.at n=5A024064
- Number of 4's in all partitions of n.at n=32A024788
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/(2*n)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=32A024845
- T(n, 2*n-5), T given by A027960.at n=13A027967
- 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=19A031585
- Numbers k > 1 such that k mod ord2(k) is even, where ord2(k) is the order of 2 mod k.at n=13A036260
- Numerators of continued fraction convergents to sqrt(461).at n=5A041878
- Numbers having four 5's in base 6.at n=16A043392
- Numbers k such that k^12 == 1 (mod 13^3).at n=42A056086
- a(n) = (9n^2 + 9n + 4)/2.at n=41A062123
- Third row of Pascal-(1,4,1) array A081579.at n=25A081587
- Numbers n such that A003313(n) = A003313(2n).at n=28A086878
- Number of compositions of n with at least 1 odd and 1 even part.at n=13A097895
- Pyramid game person numbers that have integer solutions.at n=15A135051
- Expansion of (1+3*x)/(1-x^2-2*x^3).at n=21A159285
- Terms of A177763 which have more than one such representation.at n=15A177766
- Smallest k such that 36^k mod k = n.at n=55A178197
- a(n) = 8*n^2 + 2*n + 1.at n=31A188135
- Least odd number k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x.at n=20A189560
- Number of nondecreasing arrangements of n+2 numbers in 0..6 with the last equal to 6 and each after the second equal to the sum of one or two of the preceding three.at n=44A190038