15842
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 24033
- Proper Divisor Sum (Aliquot Sum)
- 8191
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7832
- Möbius Function
- 0
- Radical
- 178
- Omega Function (Ω)
- 3
- 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
- 53
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Ramanujan's approximation to population of x^2 + y^2 <= 2^n.at n=16A000691
- Numbers n such that tau(sigma(n))= tau(tau(n)).at n=33A015730
- Indices of 9-gonal numbers that are also square.at n=6A048910
- Numbers k such that the k-th difference between 2 successive primes equals the squarefree part of k.at n=25A078691
- a(n) = 2*prime(n)^2.at n=23A079704
- Number of partitions of n into parts with at most one part not greater than 2.at n=47A121659
- 2*p^2, for p an odd prime.at n=22A143928
- a(n) = 2*Fibonacci(n)^2.at n=11A175395
- Half the number of (n+1) X 2 binary arrays with no 2 X 2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=6A184606
- Half the number of (n+1)X8 binary arrays with no 2X2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=0A184612
- T(n,k)=Half the number of (n+1)X(k+1) binary arrays with no 2X2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=21A184614
- T(n,k)=Half the number of (n+1)X(k+1) binary arrays with no 2X2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=27A184614
- Numbers k that divide A000201(k)^m for some integer m > 0, where A000201 is the lower Wythoff sequence.at n=27A185615
- Numbers the sum of whose even divisors is 2 times a prime.at n=13A195334
- Numbers such that the difference between the sum of the even divisors and the sum of the odd divisors is prime.at n=16A195382
- T(n,k) = Number of n X k 0..1 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order.at n=56A204197
- Number of partitions of n such that no part is a prime divisor of n.at n=48A237125
- 5th-largest term in the n-th row of Stern's diatomic triangle A002487.at n=17A244475
- Numbers of the form p * q^p where p and q are primes, in increasing order.at n=35A257404
- Numbers k such that k and k^2 are the sums of two nonzero squares in exactly two ways.at n=31A273293