8636
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 16128
- Proper Divisor Sum (Aliquot Sum)
- 7492
- 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
- 4032
- Möbius Function
- 0
- Radical
- 4318
- Omega Function (Ω)
- 4
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 127
- 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
- a(n) = 1 + Sum_{i=1..n} (n-i+1)*phi(i).at n=43A005598
- a(n) = sum of squares of first n positive integers congruent to 1 mod 4.at n=11A024381
- Numbers k such that phi(k)*d(k) is a multiple of sigma(k), where d(k) is the number of divisors of k.at n=32A050934
- When expressed in base 3 and then interpreted in base 7, is a multiple of the original number.at n=29A062884
- Numbers k such that k and k+1 have the same sum of unitary divisors (A034448).at n=21A064125
- Numbers k such that sigma(k) = bigomega(k) * phi(k).at n=8A067238
- Numbers k such that sigma(k) = 4*phi(k).at n=10A068390
- Numbers k such that sigma(k) = phi(k*bigomega(k)).at n=7A068400
- Numbers k such that Cyclotomic(k,k) (i.e., the value of k-th cyclotomic polynomial at k) is a prime number.at n=26A070519
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1,2}.at n=13A079990
- Numbers n such that log(n) + log_10(n) is closer to its nearest integer than any value of log(k) + log_10(k) for 1 < = k < n.at n=4A080282
- Cyclotomic(n,-n) is prime.at n=23A088875
- Recurrence sequence derived from the digits of the square root of 3 after its decimal point.at n=5A120482
- Partial sums of A006000.at n=15A133252
- Positions of zeros in A165582.at n=43A165583
- Triangle read by rows: T(n,k) is the number of 2-compositions of n having k even entries in the top row. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.at n=56A181336
- E.g.f.: A(x) = exp(x*exp(x*exp(2*x*exp(3*x*exp(...exp(n*x*exp(...))...))))).at n=5A189897
- Inverse permutation to A190134.at n=10A190135
- Constant term in the reduction by (x^2 -> x + 1) of the polynomial C(n)*x^n, where C=A000285.at n=10A192914
- Numbers k such that gcd(sigma(k), phi(k)) (A009223) attains record values.at n=19A222711