# 53 (number)

53 (fifty-three) is the natural number following 52 and preceding 54. It is the 16th prime number.

 ← 52 53 54 →
Cardinalfifty-three
Ordinal53rd
(fifty-third)
Factorizationprime
Prime16th
Divisors1, 53
Greek numeralΝΓ´
Roman numeralLIII
Binary1101012
Ternary12223
Octal658
Duodecimal4512

## In mathematics

• Fifty-three is the 16th prime number. It is also an Eisenstein prime, and a Sophie Germain prime.
• The sum of the first 53 primes is 5830, which is divisible by 53, a property shared by few other numbers.
• 53 written in hexadecimal is 35, that is, the same characters used in the decimal representation, but reversed. Four additional multiples of 53 share this property: 371 = 17316, 5141 = 141516, 99481 = 1849916, and 8520280 = 082025816. Apart from the trivial case of single-digit decimals, no other number has this property.
• 53 cannot be expressed as the sum of any integer and its base-10 digits, making 53 a self number.
• 53 is the smallest prime number that does not divide the order of any sporadic group.

Fifty-three is: