15131
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15132
- 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
- 15130
- Möbius Function
- -1
- Radical
- 15131
- 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
- 221
- 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
- 1767
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(0) = 1, a(n) = 9*n^2 + 2 for n>0.at n=41A010002
- Primes that remain prime through 3 iterations of function f(x) = 6x + 1.at n=13A023287
- Primes which when converted to base 36 make single letters or English words.at n=46A038842
- Third term of strong prime 5-tuples: p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m) > p(m+2)-p(m+1).at n=34A054810
- Primes p whose period of reciprocal equals (p-1)/5.at n=30A056210
- Primes of the form k^2 + 2.at n=15A056899
- a(0) = 0, a(1) = 1, a(n) = a(n-2)*a(n-2) + 2 for n > 1.at n=9A065653
- a(n) = p.q in decimal notation where p = prime(n) and q is the smallest prime (A066065(n)) such that the concatenation p.q is a prime.at n=35A066064
- a(1) = 2, a(n) is the smallest prime > n*a(n-1).at n=6A082282
- Duplicate of A023287.at n=13A086126
- Primes p whose Zeckendorf-expansion A014417(p) is palindromic.at n=11A095730
- Primes of the form m^k+k, with m and k > 1.at n=19A099227
- a(0)=1, a(n) = a(n-1)*a(n-1) + 2.at n=4A102847
- Primes from merging of 5 successive digits in decimal expansion of cos(1).at n=32A104961
- Number of permutations of length n which avoid the patterns 1324, 2431, 4123.at n=9A116830
- Primes for which the weight as defined in A117078 is 11 and the gap as defined in A001223 is 6.at n=30A119597
- Prime arithmetic mean of ten consecutive primes.at n=35A123096
- Primes in the sequence a(n)=n^2+3/2-1/2*(-1)^n.at n=35A125557
- Primes of the form a^2 + b^2 + c^2 such that a^4 + b^4 + c^4 is prime as well and larger than the first one.at n=31A126118
- Primes that are equal to the mean of 5 consecutive squares.at n=13A129388