12923
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12924
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12922
- Möbius Function
- -1
- Radical
- 12923
- 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
- 76
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1540
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Least prime in A031936 (lesser of 18-twins) whose distance to the next 18-twin is 2*n.at n=21A052358
- The first of two consecutive primes with equal digital sums.at n=30A066540
- Primes for which the four closest primes are smaller.at n=27A075030
- a(n) = 8*n^2 + 88*n + 43.at n=35A086760
- Numbers m such that for increasing b the numbers of zeros in base b representation of m are monotonically decreasing, 1<b<m.at n=48A089969
- Irregular primes whose indices are irregular primes of order one.at n=36A090869
- Irregular primes the indices of whose indices are irregular primes of order two.at n=0A090887
- Denominators of the convergents of the continued fraction expansion [1;1/2,1/3,1/4,...,1/n,...].at n=8A092053
- Irregular primeth recurrence: a(n+1) = a(n)-th irregular prime.at n=3A105464
- One fifth of the sum of the first n primes, when an integer.at n=25A112271
- Numbers n such that (2^p + 1)/3 is prime, where p is the n-th prime.at n=34A123176
- Primes q such that (2^p + 1)/3 is prime, where p = Prime[q]; or primes in A123176[n].at n=8A123214
- Values of m such that binomial(m, a) + binomial(m, b) divides binomial(m, a + b) for some distinct nonnegative integers a and b with a + b <= m.at n=15A140601
- Values of m for which C(m,k) + C(m,k+2) divides C(m,2k+2) for some nonnegative integer k with 2k+2 <= m.at n=5A140603
- Prime chain of 128 terms, including 104 distinct primes, consisting of the output of eight equations that alternate sequentially within a procedural expression of a single polynomial. The equations are either subsequences of x^2 - 79x + 1601 or transforms with one exception: 100x^2 - 2260x + 12959. The other four distinct equations are Euler-derived: 25x^2 - 1185x + 14083, 25x^2 - 775x + 6047, 100x^2 - 2280x + 13159, 100x^2 - 4160x + 43427.at n=4A140708
- Primes congruent to 8 mod 41.at n=39A142205
- Primes congruent to 23 mod 43.at n=37A142272
- Primes congruent to 45 mod 47.at n=36A142396
- Primes congruent to 36 mod 49.at n=36A142444
- Primes congruent to 44 mod 53.at n=26A142574