Fifty-one

The fifty-one (51) is the natural number that follows fifty and precedes fifty-two.

Mathematical properties

• It is a composite number, which has the following factors: 1, 3 and 17. The sum of its dividers 1, 3,17, 51 = 72.
• It is a pentagonal number and a centered pentagonal number (one of the few that is both at once).
• It's an 18-gonal number.
• It's a Perrin number.
• Motzkin's number.

• It's a Størmer number.
• A semi-press number.
• Lucky number.
• There are 51 different real periodic points of order 10 in the whole of Mandelbrot.
• Since 51 is the product of the different cousins of Fermat 3 and 17, a regular polygon with 51 sides is built with rule and compass.

Science

• 51 is the atomic number of the antimony.
• Messier M51 object is a classic spiral galaxy located in the constellation Canes Venatici.
• New Catalogue General NGC 51 is a lenticular galaxy located in the Andromeda constellation