1507
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1656
- Proper Divisor Sum (Aliquot Sum)
- 149
- 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
- 1360
- Möbius Function
- 1
- Radical
- 1507
- 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
- 21
- Smith Number
- yes
- 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
- Number of connected graphs with one cycle of length 4.at n=8A000368
- Number of partitions of n that do not contain 1 as a part.at n=32A002865
- Divisible only by primes congruent to 4 mod 7.at n=44A004622
- Coordination sequence T1 for Milarite.at n=24A008256
- If a, b are in the sequence, so is ab+3.at n=37A009302
- Coordination sequence T1 for Zeolite Code -ROG.at n=29A009859
- Coordination sequence for sigma-CrFe, Position Xc.at n=10A009961
- Discriminants of imaginary quadratic fields with class number 4 (negated).at n=52A013658
- a(n) = 11 a(n-1) + 8 a(n-2).at n=4A015602
- Number of elements in the set {(x,y): 1 <= x,y <= n, gcd(x,y)=1}.at n=48A018805
- a(n) = n*(25*n - 1)/2.at n=11A022282
- a(0)=a(1)=3; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=13A022403
- a(0)=3, a(1)=7; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=12A022406
- a(n) = a(n-1) + c(n+1) for n >= 3, a( ) increasing, given a(1)=1, a(2)=8; where c( ) is complement of a( ).at n=48A022954
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = A014306.at n=29A024467
- a(n) = position of n^3 + (n+1)^3 in A024670 (distinct sums of cubes of distinct positive integers).at n=46A024674
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023532, t = A001950 (upper Wythoff sequence).at n=43A025074
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = A014306.at n=28A025087
- Index of 7^n within the sequence of the numbers of the form 5^i*7^j.at n=49A025723
- Divisors of 99999999.at n=17A027890