# 63 (number)

 ← 62 63 64 →
Cardinal sixty-three
Ordinal 63rd
(sixty-third)
Factorization 32× 7
Divisors 1, 3, 7, 9, 21, 63
Roman numeral LXIII
Binary 1111112
Ternary 21003
Quaternary 3334
Quinary 2235
Senary 1436
Octal 778
Duodecimal 5312
Vigesimal 3320
Base 36 1R36

63 (sixty-three) is a natural number following 62 and preceding 64.

## In mathematics

63 is a deficient composite number with an aliquot sum of 41. It also a highly cototient number.

It is a number of the form 2n - 1 (with n=6), but it is not a Mersenne prime since n is not prime and 63 is certainly not prime either. It is also a Woodall number i.e. of the form n*2n - 1 with n=4.

It is the third Delannoy number.

It is the sum of the powers of 2 from 0 to 5, equivalently it is a repdigit in bases 2 (111111), 4 (333), and 8 (77).

In base 10 it is a Harshad number.

## In science

### Astronomy

• The Saros number of the solar eclipse series which began on -879 April 20 and ended on 401 May. The duration of Saros series 63 was 1280.1 years, and it contained 72 solar eclipses.
• The Saros number of the lunar eclipse series which began on -758 October 12 and ended on 739 March. The duration of Saros series 63 was 1496.5 years, and it contained 84 lunar eclipses.

Sixty-three is:

## In Religion

• There are 63 Tractates in the Mishna, the compilation of Jewish Law.
• There are 63 Saints in South Indian Shaivism
• There are 63 Salakapurusas (great beings) in Jain cosmology