5631
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7512
- Proper Divisor Sum (Aliquot Sum)
- 1881
- 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
- 3752
- Möbius Function
- 1
- Radical
- 5631
- 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
- 160
- Smith Number
- no
- 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
- a(n) is the solution to the postage stamp problem with n denominations and 4 stamps.at n=23A001214
- Coordination sequence T1 for Zeolite Code MTN.at n=45A008186
- 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 25.at n=22A031523
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 25.at n=2A031703
- Numbers whose set of base-12 digits is {1,3}.at n=27A032919
- Sums of 11 distinct powers of 2.at n=13A038462
- Numbers having three 7's in base 8.at n=30A043451
- Numbers whose base-4 representation contains exactly three 1's and four 3's.at n=0A045128
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 2.at n=45A050045
- Composite numbers k for which phi(k) + sigma(k) is an integer multiple of the 4th power of the number of divisors of k.at n=23A055468
- Integers whose set of prime factors (taken with multiplicity) uses each digit exactly once (i.e., is pandigital) in some base b > 1. Numbers are expressed in base 10.at n=28A058760
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 71 ).at n=27A063344
- Number of elements of order 2 in GL(2,Z_n).at n=38A066947
- Expansion of (1-x)^(-1)/(1-2*x+2*x^2-2*x^3).at n=18A077858
- a(1) = 1; then the smallest number such that both the forward and reverse n-th partial concatenation is a prime for n > 1. (Reverse concatenation is taken term-wise and not digit-wise.)at n=26A083992
- a(n) = 11*2^n - 1.at n=9A086225
- Triangle T read by rows: T(n, 1) = 2*n + 1. For 1 < k <= n, T(n, k) = 2*T(n,k-1) + 1.at n=53A087322
- Numbers m such that f(k) * 2^m - 1 is prime, where f(j) = A070826(j) and k is the number of decimal digits of 2^m.at n=31A095991
- a(n) = (n+1)*2^(n-1) - 1.at n=9A099035
- a(1) = 11, a(n) = least k such that concatenation of n copies of k with all previous concatenation gives a prime.at n=42A111477