389
domain: N
Properties
Digital Properties
- Digit Count
- 3
- 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
- 390
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 388
- Möbius Function
- -1
- Radical
- 389
- 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
- 120
- Smith 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
- 77
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- dreihundertneunundachtzig· ordinal: dreihundertneunundachtzigste
- English
- three hundred eighty-nine· ordinal: three hundred eighty-ninth
- Spanish
- trescientos ochenta y nueve· ordinal: 389º
- French
- trois cent quatre-vingt-neuf· ordinal: trois cent quatre-vingt-neufième
- Italian
- trecentoottantanove· ordinal: 389º
- Latin
- trecenti octoginta novem· ordinal: 389.
- Portuguese
- trezentos e oitenta e nove· ordinal: 389º
Appears in sequences
- Irregular primes: primes p such that at least one of the numerators of the Bernoulli numbers B_2, B_4, ..., B_{p-3} (A000367) is divisible by p.at n=19A000928
- Primes with primitive root 2.at n=31A001122
- Full reptend primes: primes with primitive root 10.at n=28A001913
- Primes p such that the congruence 2^x == 3 (mod p) is solvable.at n=45A001915
- Primes p such that the congruence 2^x = 5 (mod p) is solvable.at n=41A001916
- Pythagorean primes: primes of the form 4*k + 1.at n=35A002144
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.at n=60A002155
- Numbers k such that 39*2^k + 1 is prime.at n=21A002269
- Primes congruent to 1 or 2 modulo 4; or, primes of form x^2 + y^2; or, -1 is a square mod p.at n=36A002313
- Numbers k such that (k^2 + k + 1)/7 is prime.at n=37A002641
- Sum of logarithmic numbers.at n=5A002749
- Self numbers or Colombian numbers (numbers that are not of the form m + sum of digits of m for any m).at n=41A003052
- Primes p with a Fibonacci primitive root g, i.e., such that g^2 = g + 1 (mod p).at n=22A003147
- Numbers that are the sum of 9 positive 4th powers.at n=41A003343
- Numbers that are the sum of 11 positive 6th powers.at n=6A003367
- Numbers that are the sum of 8 positive 7th powers.at n=3A003375
- Expansion of 1/((1-2*x)*(1-x-2*x^3)).at n=7A003478
- Primes of the form 3n-1.at n=39A003627
- Primes congruent to {5, 7} mod 8.at n=40A003628
- Primes p == +- 3 (mod 8), or, primes p such that 2 is not a square mod p.at n=40A003629