84 (number)

84 (eighty-four) is the natural number following 83 and preceding 85.

<< 80 81 82 83 84 85 86 87 88 89 >> List of numbers -- Integers 0 10 20 30 40 50 60 70 80 90 >>
Cardinal <td>84 eighty-four
Ordinal <td>84th eighty-fourth
Factorization <td><math> 2^2 \cdot 3 \cdot 7</math>
Divisors <td> 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
Roman numeral	LXXXIV
Binary	01010100
Hexadecimal	54

[edit] In mathematics

Eighty-four is the sum of the first seven triangular numbers (making it a tetrahedral number), as well as the sum of a twin prime (41 + 43). Being thrice a perfect number, 84 is itself a semiperfect number.

Messier object M84, a magnitude 11.0 lenticular galaxy in the constellation Virgo
The New General Catalogue object NGC 84, a single star in the constellation Andromeda
The Saros number of the solar eclipse series which began on -181 April 14 and ended on 1099 May 22. The duration of Saros series 84 was 1280.1 years, and it contained 72 solar eclipses. Further, the number of the lunar eclipse series which began on -96 September 13 and ended on 1401 February 28. The duration of Saros series 84 was 1496.5 years, and it contained 84 lunar eclipses.