7427
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8496
- Proper Divisor Sum (Aliquot Sum)
- 1069
- 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
- 6360
- Möbius Function
- 1
- Radical
- 7427
- 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
- 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
- One half of number of non-self-conjugate partitions; also half of number of asymmetric Ferrers graphs with n nodes.at n=35A000701
- Number of partitions of n into an even number of parts.at n=35A027187
- Cube root of A030697.at n=15A030698
- Numbers k such that 139*2^k-1 is prime.at n=36A050595
- Indices of primes in sequence defined by A(0) = 37, A(n) = 10*A(n-1) - 3 for n > 0.at n=10A101840
- 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, 0, 0), (0, -1, 1), (0, 0, 1), (0, 1, -1), (1, 0, 1)}.at n=7A150474
- Number of lines through at least 2 points of a 4 X n grid of points.at n=45A160844
- Number of partitions of 2n+1 of type OO (see Comments).at n=17A236914
- G.f. A(x) = Sum_{n=-oo..+oo} x^n * (1 + x^n)^(2*n).at n=55A260147
- A292764(n)/2.at n=14A292765
- The number of seconds after midnight corresponding to prime time primes, i.e., primes of the form HMMSS with primes H < 24 and MM, SS < 60, cf. A295013.at n=6A295003
- The number of seconds after midnight (3600*H + 60*MM + SS) corresponding to prime time numbers A295014, i.e., numbers of the form HMMSS with primes H < 24 and MM, SS < 60.at n=31A295004
- Number of integer partitions of n with reverse-alternating sum < 0.at n=35A344608
- Records in A361321.at n=25A361325
- Array read by downward antidiagonals: A(n,k) = (k+2)*A(n-1,k+1) + Sum_{j=0..k} A(n-1,j) with A(0,k) = 1, n >= 0, k >= 0.at n=32A370380