7249
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7920
- Proper Divisor Sum (Aliquot Sum)
- 671
- 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
- 6580
- Möbius Function
- 1
- Radical
- 7249
- 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
- 70
- 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
- a(n) = C(n+2,3) + C(n,3) + C(n-1,3).at n=24A006004
- Eleven iterations of Reverse and Add are needed to reach a palindrome.at n=10A015992
- a(n) = [ (3rd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+2 positive integers congruent to 1 mod 3}.at n=10A024220
- Numbers whose base-5 representation contains exactly two 2's and three 4's.at n=24A045288
- Partial sums of A048697.at n=8A048773
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 99 ).at n=26A063372
- Numbers which need eleven 'Reverse and Add' steps to reach a palindrome.at n=9A065216
- Numbers k such that k^5 + 4^k is prime.at n=8A075982
- Consider 3 X 3 matrix M = [0 1 0 / 0 0 1 / 5 2 0]; a(n) = the center term in M^n * [1 1 1].at n=11A094248
- a(n)=x is the first term in chain of consecutive integers, for all of which the value of sigma[x] is divisible by 6.at n=21A097016
- a(n)=x is the first term in chain of consecutive integers, for all of which the value of sigma[x] is divisible by 6.at n=22A097016
- a(n)=x is the first term in chain of consecutive integers, for all of which the value of sigma[x] is divisible by 6.at n=23A097016
- Triangle, read by rows, where the n-th diagonal equals the n-th row transformed by triangle A008459 (squared binomial coefficients).at n=74A097084
- n times n+1 gives the concatenation of two numbers m and m-5.at n=2A116251
- Start with 1 and repeatedly reverse the digits and add 48 to get the next term.at n=28A118160
- Sums of three consecutive hexagonal numbers.at n=34A129109
- Triangle, read by rows of 2n+1 terms, where T(n,k) = T(n,k-1) + T(n-1,k-1) for 2n>=k>0, T(n,2n-1) = T(n,2n-2) + T(n-1,n-1) and T(n,2n) = T(n,2n-1) + T(n-1,n-1) for n>0, with T(n,0) = T(n-1,n-1) for n>0 and T(0,0) = 1.at n=44A132289
- Number of compositions a(1),...,a(k) of n, for some k, such that a(i+1) <= a(i) + 1 for 1 <= i < k and a(1) <= a(k) + 1.at n=16A168445
- Number of 0..n arrays x(0..3) of 4 elements with zero 3rd differences.at n=27A200155
- Number of distinct sums of reciprocals of parts of partitions of n.at n=34A212187