15391
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15392
- 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
- 15390
- Möbius Function
- -1
- Radical
- 15391
- 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
- 177
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1799
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 74 ones.at n=12A031842
- Third term of weak prime sextet: p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2).at n=5A054830
- 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=4A054831
- Fourth term of weak prime septet: 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) < p(m+3)-p(m+2).at n=0A054837
- First member of a prime quadruple in a 2p-1 progression.at n=9A057327
- First member of a prime 5-tuple in a 2p-1 progression.at n=2A057328
- Primes with 12 as smallest positive primitive root.at n=3A061325
- a(n) is smallest prime > 11*a(n-1), a(1) = 11.at n=3A065543
- a(1) = 9, then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=29A083995
- Primes p such that p-1 and p+1 are both divisible by fourth powers.at n=11A086709
- Primes p=prime(k) such that in binary representation k is a substring of p.at n=13A091021
- 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=24A094749
- Value of C in y = x^2 + 9x + C such that y is prime for all x = 0 to 5.at n=13A097437
- Least j > 1 such that j^2 = (4*n^2 + 2)*(k^2) + (4*n^2 + 2)*k + 1.at n=15A106231
- Primes starting a Cunningham chain of the second kind of length 5.at n=2A110022
- Smallest primes starting a complete four iterations Cunningham chain of the first or second kind.at n=3A110027
- Integers i such that 9*i = 25 X i, but 17*i is not 49 X i.at n=18A115811
- Primes for which the level is equal to 9 in A117563.at n=38A118481
- Primes of the form 55x^2+10xy+199y^2.at n=26A140632
- Primes of the form 210k + 61.at n=38A140854