15757
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18016
- Proper Divisor Sum (Aliquot Sum)
- 2259
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13500
- Möbius Function
- 1
- Radical
- 15757
- 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
- 27
- 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
- Number of dyslexic planted planar trees with n nodes.at n=11A032128
- Denominators of continued fraction convergents to sqrt(115).at n=14A041209
- Numbers whose base-5 representation contains exactly three 0's and three 1's.at n=19A045172
- Composite numbers n such that 8*n^2-2*n-1 divides the primitive part U(n) of Fibonacci(n).at n=31A159234
- Numbers k such that Sum_{i=1..k} i^7 divides Product_{i=1..k} i^7.at n=16A166607
- Base-6 analog of A208059.at n=53A212995
- Composite numbers coprime to 6 such that A179382(n) = A000265(n-1), the odd part of n-1.at n=26A225913
- Fundamental discriminants d uniquely characterizing all complex biquadratic fields Q(sqrt(-3),sqrt(d)) which have 3-class group of type (3,3) and second 3-class group isomorphic to SmallGroup(729,95).at n=5A250239
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 950", based on the 5-celled von Neumann neighborhood.at n=28A273829
- Semiprime numbers whose digit string can be partitioned into three parts such that the product of the first two parts equals the third part.at n=36A280636
- Numbers n such that N = n^3 is a twin rank (A002822: 6N +- 1 are twin primes).at n=46A326234
- Smallest possible value of |Sum_{k=0..n} (+-) 2^k * 3^(n-k)|, where each (+-) can be either plus or minus sign, independently for each term in the sum.at n=29A349544
- Number of integer compositions of n into parts that are alternately unequal and equal.at n=32A357644
- Number of iterations before a repeated value, or -1 if this never occurs, when starting at k = 1 and repeating k = k*n if k does not contain any adjacent equal digits, else k = k with all adjacent equal digits replaced by a single copy of the same digit.at n=24A368940
- Coefficient of x^n in the expansion of 1/( (1-x)^2 - x^3 )^n.at n=6A370281