Roman numerals are represented by seven different letters: I, V, X, L, C, D and M. Which represent the numbers 1, 5, 10, 50, 100, 500 and 1,000. These seven letters are used to make thousands of numbers.

For example 8 is VIII.

Change language7 in English words

seven

odd

Square root

2.6457513110646

Binary number

111

7 in Fibonacci Sequence

No

This number consist from

1 digits

Sum of 1 digits (7)

7

Prime

7. It's the perfect number. 7 days, 7 colors in the rainbow. It's a prime number. It's an odd number.

Mentions:7

Considered a "lucky" number in Western cultures.

Mentions:

World:
7 continents in the world.
7 wonders of the ancient world.
7 colors in the rainbow.
7 musical notes.
7 phases of the moon.
7 days of the week.
Religion:
7 days of Creation
7 deadly sins
7 heavens in Islam
Chemistry:
7 is the neutral pH value.
7 crystal lattice systems.
Literature:
7 stages of life in Shakespeare’s As You Like It.
7 Harry Potter novels.
7 detectives in Enid Blyton’s The Secret Seven.
Computers:
7 layers of OSI model.
7 logic gates - NOT, NOR, XNOR, XOR, AND, NAND, and OR.
And most important of all:

Mentions:7