10639
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 10640
- 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
- 10638
- Möbius Function
- -1
- Radical
- 10639
- 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
- 55
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1298
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k where |cos(k)| (or |cosec(k)| or |cot(k)|) decreases monotonically to 0; also numbers k where |tan(k)| (or |sec(k)|, or |sin(k)|) increases.at n=35A004112
- Primes that remain prime through 3 iterations of function f(x) = 2x + 5.at n=32A023274
- Primes that remain prime through 4 iterations of function f(x) = 2x + 5.at n=14A023304
- [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 2 mod 3}.at n=13A024402
- Least k such that tan(k) > tan(a(n-1)), for n >= 1, where a(0) = 0.at n=46A024814
- Expansion of Product_{i>=1} (1-x^i)^(1/i); also of exp(- Sum_{n>=1}(d(n)*x^n/n)) where d(n) is the number of divisors of n.at n=9A028343
- Numbers k where cos(k) decreases monotonically to 0.at n=18A046957
- Numbers k where sin(k) increases monotonically to 1 (or cosec(k) decreases).at n=22A046959
- Primes p such that p^9 reversed is also prime.at n=31A059702
- Numbers k such that floor(tan(k)) > floor(tan(m)) for all m < k.at n=43A063537
- Five-digit distinct-digit primes.at n=21A074671
- a(1) = 1, a(n) = smallest prime number not already used such that concatenation of a(k) and a(n) is composite for all k = 1 to n-1.at n=39A075612
- Largest prime < n^3.at n=20A077037
- Primes p such that p-1 and p+1 are both divisible by cubes (other than 1).at n=38A086708
- Numbers k such that 4*10^k + 6*R_k + 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=22A099017
- Number of even parts in all partitions of n into distinct parts.at n=51A116680
- Prime numbers of the form 24*p + 7 where p is prime.at n=34A135985
- Record indices of the ratio A002375(n) / n (Goldbach conjecture related).at n=41A137820
- Primes congruent to 6 mod 31.at n=43A142010
- Primes congruent to 20 mod 37.at n=37A142129