285 (number)

In mathematics

• 285 is an odd composite number.
• 285 is the 9th square pyramidal number. That means it is the sum of a number of consecutive perfect squares starting with 1. For 285, it is the sum of all of the single digits' perfect squares.
• 285 is the number of variations possible with a binary rooted tree with 13 points. A binary rooted tree means that it always begins with 1 point that is rooted. From there, each point can branch in up to two directions.
• 285 is a sphenic number which means that it has three distinct prime factors.
• 285 is a Harshad number. That means that it is divisible by the sum of its digits. 285 is divisible by 15.
• 285 is a repdigit number in base 7. In base 7, 285 is 555.
• 285 is a very symmetric number. If flipped horizontally, these numbers are symmetrical.