7877
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
- 2
- Divisor Sum
- 7878
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 7876
- Möbius Function
- -1
- Radical
- 7877
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 26
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 995
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 13.at n=41A020352
- Primes that contain digits 7 and 8 only.at n=4A020470
- Expansion of Product_{m>=1} (1+q^m)^(-4).at n=24A022599
- Primes that remain prime through 3 iterations of function f(x) = 9x + 8.at n=24A023298
- Write 1,2,... in a clockwise spiral; sequence gives numbers on positive x axis.at n=44A033951
- Smallest n-digit prime containing only the digits 7 and 8, or 0 if no such prime exists.at n=3A036949
- Numbers having three 7's in base 10.at n=32A043519
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 19.at n=24A050968
- Primes whose decimal expansion is a concatenation of two or more consecutive decreasing numbers (no leading zeros allowed).at n=8A052088
- Primes formed by concatenating k with k-1.at n=8A052089
- Fourth term of strong prime quintets: p(m-2)-p(m-3) > p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m).at n=21A054811
- Primes of the form k(k+1)/2+2 (i.e., two more than a triangular number).at n=25A055472
- Primes q of form q=10p+7, where p is also prime.at n=35A055783
- Primes starting and ending with 7.at n=31A062334
- Primes in which neighboring digits differ at most by 1.at n=34A068148
- Duplicate of A052089.at n=8A068699
- Primes on axis of Ulam square spiral (with rows ... / 7 8 9 / 6 1 2 / 5 4 3 / ... ) with origin at (1).at n=40A078784
- First row of square array A082011.at n=42A082012
- Primes that are a concatenation of a prime and its first digit.at n=21A085414
- (1,3) entry of powers of the orthogonal design shown in A090592.at n=10A089181