15401
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15402
- 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
- 15400
- Möbius Function
- -1
- Radical
- 15401
- 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
- 146
- 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
- 1800
- 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 odd period and if the last term of the periodic part is deleted the two central terms are both 49.at n=0A031637
- a(n) = prime(100*n).at n=17A031921
- Initial terms of '4-block' primes as described in A032591.at n=20A032592
- Fifth term of weak prime quintets: p(m-3)-p(m-4) < p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1).at n=38A054827
- Fourth term of weak prime sextet: p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1).at n=5A054831
- Fifth term of weak prime sextet: p(m-3)-p(m-4) < p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m).at n=4A054832
- Fifth term of weak prime septet: p(m-3)-p(m-4) < p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1).at n=0A054838
- Primes p such that phi(p+1) = phi(p-1).at n=7A067890
- Primes p such that 2^p-1 and the p-th Fibonacci number have a common factor. Prime terms of A074776.at n=5A080050
- Primes of the form 16*m^2 + 25, m=1,3,5,...at n=7A087856
- Primes of the form 16*m^2 + 25 for m=1,2,3,...at n=14A087857
- Primes of the form 5k^2 + 5k + 1.at n=29A090562
- Sum of largest parts of all partitions of n into odd parts.at n=39A092322
- Triangle read by rows in which the n-th row contains the least set of n successive primes whose successive difference forms an arithmetic progression with common difference 2, (successive even numbers).at n=25A094749
- Smallest odd prime p such that n=(p-1)/ord_p(3).at n=34A101209
- a(n) = prime(x) - pi(x) where x is the least x such that (prime(x+1) - pi(x+1)) - (prime(x) - pi(x)) = n.at n=43A111183
- a(n) = 5*F(n)^2 + 5*F(n) + 1, where F(n) = Fibonacci(n).at n=10A124297
- Smallest prime p such that the maximum run length of consecutive quadratic nonresidues modulo p is n.at n=21A129201
- Primes of the form 210n+71.at n=37A140856
- Primes congruent to 32 mod 47.at n=37A142383