1519
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 1824
- Proper Divisor Sum (Aliquot Sum)
- 305
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1260
- Möbius Function
- 0
- Radical
- 217
- Omega Function (Ω)
- 3
- 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
- 153
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=22A003215
- a(n) = 1000*log_10(n) rounded to the nearest integer.at n=32A004226
- a(n) = ceiling(1000*log_10(n)).at n=32A004227
- a(n) = (n + 3)*(n^2 + 6*n + 2)/6.at n=18A005286
- Related to representations as sums of Fibonacci numbers.at n=35A006133
- Coordination sequence T3 for Zeolite Code NES.at n=25A008207
- a(n) = n^2 - 2.at n=38A008865
- Expansion of e.g.f. sinh(sin(x)*exp(x)).at n=7A009594
- Coordination sequence for FeS2-Pyrite, S position.at n=18A009956
- a(n) = |1^3 - 2^3 + 3^3 - 4^3 + ... + (-1)^(n+1)*n^3|.at n=14A011934
- Numbers n such that phi(n) * sigma(n) + 16 is a perfect square.at n=34A015729
- Six iterations of Reverse and Add are needed to reach a palindrome.at n=25A015984
- Alkane (or paraffin) numbers l(9,n).at n=8A018210
- Alkane (or paraffin) numbers l(11,n).at n=6A018212
- Form a permutation of the positive integers, p_1, p_2, ..., such that the average of each initial segment is an integer, using the greedy algorithm to define p_n; sequence gives p_1 + ... + p_n.at n=48A019445
- Coordination sequence T2 for Zeolite Code CGF.at n=27A019452
- Coordination sequence T4 for Zeolite Code CGF.at n=27A019454
- Pseudoprimes to base 30.at n=17A020158
- Pseudoprimes to base 67.at n=21A020195
- Pseudoprimes to base 68.at n=28A020196