15151
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15400
- Proper Divisor Sum (Aliquot Sum)
- 249
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14904
- Möbius Function
- 1
- Radical
- 15151
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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
- Octal palindromes which are also primes.at n=24A006341
- a(n) = L(n+1) + c(n) where L(k) = k-th Lucas number and c(n) is n-th number that is 1 or not a Lucas number.at n=18A022802
- Sum of n-th Lucas number greater than 3 and n-th number that is 1 or is not a Fibonacci number.at n=17A023489
- a(n) = b(n) + d(n), where b(n) = (n-th Lucas number > 3) and d(n) = (n-th non-Lucas number).at n=17A023495
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 13 ones.at n=27A031781
- Numbers k such that 161*2^k+1 is prime.at n=19A032457
- Numbers whose consecutive digits differ by 4.at n=53A048406
- Numbers n such that n and 2n+1 are both palindromes.at n=29A069881
- Smallest palindromic number relatively prime to all the previous terms.at n=42A083137
- Composite numbers in A083137.at n=8A083138
- Antidiagonal sums of table A083362.at n=30A083364
- Palindromes k such that 3k + 1 is also a palindrome.at n=16A083829
- Palindromic brilliant numbers.at n=12A084350
- Palindromes with more than 3 digits in which the absolute difference of a pair of successive digits is identical.at n=17A085109
- Palindromic numbers with property that sum of digits is prime and number of prime digits is prime.at n=20A093807
- Expansion of 1/((1+x+x^2)*(1+5*x+x^2)).at n=6A110311
- Both n and the reverse of n are brilliant numbers (A078972).at n=32A115655
- Palindromic primes in base 7 (written in base 7).at n=15A117702
- Palindromic primes in base 9 (written in base 9).at n=23A117703
- Palindromic composites such that some digit permutation is prime.at n=36A119378