7252
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
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 15162
- Proper Divisor Sum (Aliquot Sum)
- 7910
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3024
- Möbius Function
- 0
- Radical
- 518
- Omega Function (Ω)
- 5
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 18
- 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
- yes
- Odd
- no
Appears in sequences
- Number of 6-ary search trees on n keys.at n=14A019500
- Fibonacci sequence beginning 2, 18.at n=14A022371
- Twice second pentagonal numbers.at n=49A049451
- Number of binary Lyndon words with an even number of 1's.at n=17A051841
- T(n,n-3), array T as in A054110.at n=25A054112
- Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.at n=14A070980
- Sums of groups in A075639.at n=13A075640
- Multiples of 7 using only prime digits (2, 3, 5 and 7).at n=39A077536
- Numbers n with property that n is not a power of 2 and the finite sequence n, f(n), f(f(n)), ...., 1 in the Collatz (or 3x + 1) problem contains exactly one prime. (The earliest "1" is meant.)at n=35A078440
- a(n) = lcm(n, A025586(n)), least common multiple of n and largest value in 3x+1 iteration list started at n.at n=48A087259
- Expansion of 2*x*(x+2) / ((x-1)*(x^2+6*x-1)).at n=4A089154
- Numbers k such that the numerator of Bernoulli(2k) is divisible by the square of 37, the first irregular prime.at n=26A092230
- An accelerator sequence for Catalan's constant.at n=14A094649
- Where A007535 reaches a record.at n=28A098653
- Let M(n) be the n X n matrix m(i,j)=min(i,j) for 1<=i,j<=n; then a(n) is the trace of M(n)^(-7).at n=3A114359
- a(n) = RMS( A141393(0) through A141393(n) ).at n=13A141394
- a(n) = Sum_{j=1..prime(n)-1} floor(j^2/prime(n)).at n=34A165993
- Rectangular array read by antidiagonals: row q has generating function F_q(x) = sum_{r=0,...,q-1} ((q-r)*(-1)^r*binomial(2*q-r,r)*x^r) / sum_{s=0,...,q} ((-1)^s*binomial(2*q-s,s)*x^s), where q=1,2,....at n=62A185095
- Sequence read from antidiagonals of rectangular array with entry in row n and column q given by T(n,q) = 2^(2*n)*(Sum_{j=1..n+1} (cos(j*Pi/(2*q+1)))^(2*n)), n >= 0, q >= 1.at n=58A186740
- a(n) is the number of basic ideals in the standard Borel subalgebra of the untwisted affine Lie algebra sl_n.at n=6A194460