7390
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13320
- Proper Divisor Sum (Aliquot Sum)
- 5930
- 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
- 2952
- Möbius Function
- -1
- Radical
- 7390
- Omega Function (Ω)
- 3
- 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
- 207
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers whose set of base-9 digits is {1,2}.at n=32A032930
- Shifts left under transform T where Ta is (identity) DCONV a.at n=35A038046
- Numbers having four 1's in base 9.at n=12A043460
- Numbers whose base-3 representation has exactly 9 runs.at n=4A043589
- Numbers n such that number of runs in the base 3 representation of n is congruent to 1 mod 8.at n=20A043799
- Numbers n such that number of runs in the base 3 representation of n is congruent to 0 mod 9.at n=4A043806
- Numbers k such that number of runs in the base 3 representation of k is congruent to 9 mod 10.at n=4A043824
- 30*a(n) is the gap between sexy prime triples in the n-th sexy prime triple triple whose initial term is 7.at n=12A090776
- a(n) = 3*A146085(n) - 2.at n=41A146091
- Numbers that are the product of 3 distinct primes a,b and c, such that a^2+b^2+c^2 is the average of a twin prime pair.at n=34A176879
- Number of n-digit Kaprekar numbers (A006886).at n=47A194232
- Number of partitions p of n such that mean(p) < multiplicity(min(p)).at n=35A240203
- Partial sums of A255743.at n=16A255764
- Number of (n+2) X (6+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.at n=38A255799
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + 2*b(n-2) - b(n-3), where a(0) = 1, a(1) = 3, a(2) = 5, b(0) = 2, b(1) = 4, b(2) = 6, and (a(n)) and (b(n)) are increasing complementary sequences.at n=14A295361
- Number of nX6 0..1 arrays with every element unequal to 0, 1 or 5 king-move adjacent elements, with upper left element zero.at n=9A303717
- Records in A338338.at n=42A338348
- a(0) = 0, a(1) = 1; a(2*n) = 9*a(n), a(2*n+1) = a(n) + a(n+1).at n=33A342615
- a(n) = [x^n] ( E(x)/E(-x) )^n where E(x)= exp( Sum_{k >= 1} A005259(k)*x^k/k ).at n=3A362723