15149
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15150
- 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
- 15148
- Möbius Function
- -1
- Radical
- 15149
- 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
- 84
- 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
- 1770
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = L(n+2) + c(n) where L(k) is the k-th Lucas number and c(n) is the n-th number that is 1 or 3 or is not a Lucas number.at n=17A022810
- Graham-Sloane-type lower bound on the size of a ternary (n,3,7) constant-weight code.at n=7A030507
- Primes of the form 2*n^2 + 11.at n=42A050265
- Primes p such that p, p+12, p+24 are consecutive primes.at n=10A052188
- 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=32A126118
- List of triples of primes with common difference 12.at n=30A128312
- Primes congruent to 13 mod 43.at n=39A142262
- Primes congruent to 15 mod 47.at n=40A142366
- Primes congruent to 44 mod 53.at n=31A142574
- Primes congruent to 45 mod 59.at n=31A142772
- Primes congruent to 21 mod 61.at n=28A142819
- Middle of 3 consecutive prime numbers, p1, p2, p3, such that p1*p2*p3*d1*d2 = average of twin prime pairs; d1 (delta) = p2 - p1, d2 (delta) = p3 - p2.at n=16A153410
- Numerator of A166100(A166101(n))/A166102(n).at n=28A166272
- Emirps whose only prime digits are 5's.at n=18A179036
- Emirps with a 5 as the only prime digit.at n=14A179037
- Final prime adjoined in the smallest term of A019518 divisible by 47^n.at n=1A185686
- Consider two consecutive primes {p,q} such that {P=2p-q,Q=2q-p} are both prime. Sequence gives lesser primes p.at n=32A186169
- Primes of the form 2*n^2+38*n+17.at n=32A243890
- Numbers k such that both numbers k and k+1 are in the sequence A248903.at n=10A248894
- Numbers k such that A248891(k) = 3.at n=48A248903