7878
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 17136
- Proper Divisor Sum (Aliquot Sum)
- 9258
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2400
- Möbius Function
- 1
- Radical
- 7878
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 26
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Composite numbers n such that sigma(n+24) = sigma(n) + 24.at n=14A054983
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 77 ).at n=35A063350
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 93 ).at n=33A063366
- Satisfies a(n)/A079159(n) = p_n, the n-th prime (n>0), a(0)=1.at n=26A079161
- Where n first appears in A093320.at n=6A094162
- a(1) = 1; for n > 1, a(n) is the least k > a(n-1) such that a(n) + a(n-1) is square and a(n) - a(n-1) is prime.at n=20A108972
- Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=18A117313
- Sums of three consecutive pentagonal numbers.at n=41A129863
- Number of isomorphism classes of toric log del Pezzo surfaces with index L = n.at n=27A145581
- 3 times 10-gonal (or decagonal) numbers: a(n) = 3*n*(4*n-3).at n=26A152767
- a(n) = 4*n^2 + 3*n + 2.at n=44A185669
- Numbers n such that 4n+1 is a palindromic prime.at n=24A192261
- a(n) = smallest k having at least three prime divisors d such that (d + n) | (k + n).at n=41A202158
- Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly three clockwise edge increases.at n=4A206065
- Number of (n+1)X6 0..2 arrays with every 2X3 or 3X2 subblock having exactly three clockwise edge increases.at n=0A206069
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X3 or 3X2 subblock having exactly three clockwise edge increases.at n=14A206072
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X3 or 3X2 subblock having exactly three clockwise edge increases.at n=10A206072
- Number of n X n 0..1 arrays avoiding 0 1 0 horizontally and 1 0 0 vertically.at n=3A206884
- Number of nX4 0..1 arrays avoiding 0 1 0 horizontally and 1 0 0 vertically.at n=3A206885
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 1 0 horizontally and 1 0 0 vertically.at n=24A206889