1630
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 2952
- Proper Divisor Sum (Aliquot Sum)
- 1322
- 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
- 648
- Möbius Function
- -1
- Radical
- 1630
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 135
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- A self-generating sequence: a(1)=1, a(2)=2, a(n+1) chosen so that a(n+1)-a(n-1) is the first number not obtainable as a(j)-a(i) for 1<=i<j<=n.at n=45A001149
- Numbers k such that k^64 + 1 is prime.at n=16A006316
- Number of tree-rooted toroidal maps with 2 faces and n vertices and without isthmuses.at n=2A006436
- Coordination sequence occurring in Zeolite Codes AFG, CAN, LIO, LOS.at n=28A008013
- Coordination sequence T6 for Zeolite Code DDR.at n=25A008076
- Coordination sequence T4 for Zeolite Code DOH.at n=25A008081
- Expansion of e.g.f. sec(sec(x)*log(x+1)).at n=6A012778
- Expansion of 1/(1-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19).at n=60A017895
- Expansion of 1/((1-3x)(1-6x)(1-7x)).at n=3A017931
- Expansion of Product_{m>=1} (1 + m*q^m)^10.at n=4A022638
- Numbers k such that Fibonacci(k) == -55 (mod k).at n=33A023170
- a(n+1) = a(n) converted to base 8 from base 7 (written in base 10).at n=30A023388
- Index of 7^n within the sequence of the numbers of the form 5^i*7^j.at n=51A025723
- Sums of five consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2.at n=16A027578
- Number of achiral polyominoes with n cells.at n=14A030227
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 16.at n=36A031514
- Numbers k such that 33*2^k+1 is prime.at n=18A032366
- Numbers whose set of base-9 digits is {1,2}.at n=26A032930
- Every run of digits of n in base 9 has length 2.at n=17A033007
- Numbers whose base-9 expansion has no run of digits with length < 2.at n=26A033022