87 (number)

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← 86 87 88 →
Cardinal eighty-seven
Ordinal 87th
(eighty-seventh)
Factorization 3 × 29
Divisors 1, 3, 29, 87
Roman numeral LXXXVII
Binary 10101112
Ternary 100203
Quaternary 11134
Quinary 3225
Senary 2236
Octal 1278
Duodecimal 7312
Hexadecimal 5716
Vigesimal 4720
Base 36 2F36

87 (eighty-seven) is the natural number following 86 and preceding 88.

In mathematics[edit]

87 is:

  • the sum of the squares of the first four primes.
  • the sum of the sums of the divisors of the first 10 positive integers.[1]
  • the twenty-sixth distinct semiprime and the eighth of the form (3.q).
  • 5! - 4! - 3! - 2! - 1! = 87

The aliquot sum of 87 is 33 within the aliquot sequence (87,33,15,9,4,3,1,0) 86 being the eighteenth composite number in the 3-aliquot tree.

In sports[edit]

In other fields[edit]

Eighty-seven is also:


References[edit]