# 97 (number)

 ← 96 97 98 →
Cardinal ninety-seven
Ordinal 97th
(ninety-seventh)
Factorization prime
Prime 25th
Divisors 1, 97
Roman numeral XCVII
Binary 11000012
Ternary 101213
Quaternary 12014
Quinary 3425
Senary 2416
Octal 1418
Duodecimal 8112
Vigesimal 4H20
Base 36 2P36

97 (ninety-seven) is the natural number following 96 and preceding 98.

## In mathematics

97 is:

• the 25th prime number (the largest two-digit prime number in base 10), following 89 and preceding 101.
• a Proth prime as it is 3 × 25 + 1.[1]
• the eleventh member of the Mian–Chowla sequence.[2]
• the smallest factor of one more than the product of the first twenty-five terms of the Euclid–Mullin sequence, making it the twenty-sixth term.[3]
• a self number in base 10, since there is no integer that added to its own digits adds up to 97.[4]
• the highest two digit number where the sum of its digits is a square.

The numbers 97, 907, 9007, 90007 and 900007 are happy primes. However, 9000007 (read as nine million seven) is composite and has the factorisation 277 × 32491.

Ninety-seven is: