7255
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8712
- Proper Divisor Sum (Aliquot Sum)
- 1457
- 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
- 5800
- Möbius Function
- 1
- Radical
- 7255
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 57
- 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) = Sum_{i=0..n-1} a(i) * a(n-i), a(0) = 1, a(1) = 5.at n=7A014434
- Expansion of 1/(1-x^3-x^4-x^5-x^6-x^7-x^8).at n=29A017821
- Numbers k such that the continued fraction for sqrt(k) has period 56.at n=30A020395
- Number of partitions of n with equal number of parts congruent to each of 0 and 3 (mod 4).at n=40A035542
- Base-7 palindromes that start with 3.at n=17A043017
- Numbers n such that 141*2^n-1 is prime.at n=16A050596
- The array in A059216 read by antidiagonals in 'up' direction.at n=42A059217
- The array in A059216 read by antidiagonals in the direction in which it was constructed.at n=38A059234
- Triangle T(n,k) (n >= 2, k = 3..n+floor(n/2)) giving number of bicoverings of an n-set with k blocks.at n=15A059443
- Number of 6-block bicoverings of an n-set.at n=5A059947
- Integer part of (Product(n^((1 + log(1 + i))/(1 + i^2)), {i, 1, n})).at n=46A062492
- Average of terms in n-th row of A077316.at n=42A077319
- Class numbers of fields in A085715.at n=19A085716
- Numbers n such that p(3n) is prime, where p(n) is the number of partitions of n.at n=39A111389
- Start with 1 and repeatedly reverse the digits and add 36 to get the next term.at n=20A118536
- Number of integer-sided triangles with all sides <= n and sides relatively prime.at n=45A123324
- Where records occur in A134204.at n=49A133245
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (1, -1, 0), (1, 0, 1), (1, 1, -1)}.at n=8A148994
- Numerator of the Harary number for the cycle graph C_n.at n=19A160046
- a(n) is the smallest integer > a(n-1) such that a(n) shares no digit with a(n-1) and c=a(n-1)+a(n), and also a(n-1) shares no digit with c.at n=21A166461