16139
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 16140
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16138
- Möbius Function
- -1
- Radical
- 16139
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 190
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1878
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Array (a frieze pattern) defined by a(n,k) = (a(n-1,k)*a(n-1,k+1) - 1) / a(n-2,k+1), read by antidiagonals.at n=42A007754
- Primes that remain prime through 3 iterations of function f(x) = 8x + 7.at n=8A023294
- Recursive prime generating sequence.at n=53A039726
- Smaller of twin prime pairs in consecutively larger seas of composite numbers.at n=25A046928
- Primes p such that there is no Carmichael number pqr, p<q<r q, r primes.at n=19A051663
- Denominators of continued fraction for alternating factorial.at n=13A056922
- Column 2 of A007754.at n=6A058799
- Smallest prime larger than square of n-th prime.at n=30A062772
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 8*p+1 (A023228) is also prime.at n=37A075706
- If a,b are prime numbers satisfying the Diophantine equation a^3+b^3=c^2, then a is -1 mod 12 and b is 1 mod 12, or vice versa. Choose 'a' to be -1 mod 12. This is the sequence of 'a' values, sorted by the magnitude of c.at n=18A099806
- Lesser of a twin-prime pair where both are expressible as the sum of two triangular numbers.at n=29A118638
- Number of compositions of n which avoid the pattern 112.at n=17A128742
- Lesser of twin primes isolated from neighboring primes by +- 10 (or more).at n=30A138063
- Primes of the form k^2 + 10.at n=21A138355
- Primes congruent to 18 mod 47.at n=39A142369
- Primes congruent to 27 mod 53.at n=33A142557
- Primes congruent to 32 mod 59.at n=29A142759
- Primes congruent to 35 mod 61.at n=32A142833
- Values of p in A145767.at n=19A145797
- Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 0100-1100-1111 pattern in any orientation.at n=10A146784