Eighty-four (84, LXXXIV) is the natural number following eighty-three and preceeding eighty-five. It's the sum of the first seven triangular numbers, as well as the sum of a twin prime (41 + 43).
- Hexadecimal: 54
- Binary: 01010100
- Factors: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84.
- Factorization:
- Ordinal number: eighty-fourth
- the atomic number of polonium (Po)
- the model number of AGM-84 Harpoon
- WGS 84
- the house number of 84 Avenue Foch
- the number of the French department Vaucluse
- the designation of Interstate 84, a freeway that runs from Oregon to Utah and from Pennsylvania to Massachusetts.
- the code for international direct dial phone calls to Vietnam
- a town in Pennsylvania: Eighty Four
- the year AD 84 or AD 1984.