15191
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16584
- Proper Divisor Sum (Aliquot Sum)
- 1393
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13800
- Möbius Function
- 1
- Radical
- 15191
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 133
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- G.f.: (1 + x^4 + x^7 + 2*x^8 + x^9 + x^12 + x^16)/Product_{i=1..8} (1 - x^i).at n=35A003405
- Strong pseudoprimes to base 75.at n=25A020301
- Indices of primes in sequence defined by A(0) = 77, A(n) = 10*A(n-1) + 27 for n > 0.at n=9A056263
- Larger terms of the pairs (a < b) in the sequence {a,b}-> {Max[{a,b}]-Min[{a,b}],k*Min[{a,b}]} with k=3 and the first pair {a=1,b=2}. See A075256.at n=41A075258
- G.f.: (1+x)/Product_{m>0} (1 - x^m).at n=32A084376
- Semiprimes in A054552.at n=21A113690
- Number of parts that are multiples of 3 in all partitions of n.at n=32A116635
- Numerator of Euler(n, 10/31).at n=3A157691
- Nonprime numbers with all divisors starting and ending with digit 1.at n=25A208261
- Triangle read by rows: number of idempotents of rank k in partition monoid P_n.at n=16A256040
- Expansion of Product_{k>=1} 1/(1-x^(3*k-1))^k.at n=50A262876
- Strings of 5 digits from 1...9, such that no formula using the single digits in the given order exists that evaluates to 0.at n=27A288355
- Composite numbers k with its divisors having the property that the last digit of every divisor is the same as the first digit of the next divisor.at n=28A307858