# 97 (number)

 ← 96 97 98 →
Cardinalninety-seven
Ordinal97th
(ninety-seventh)
Factorizationprime
Prime25th
Divisors1, 97
Greek numeralϞΖ´
Roman numeralXCVII
Binary11000012
Ternary101213
Quaternary12014
Quinary3425
Senary2416
Octal1418
Duodecimal8112
Vigesimal4H20
Base 362P36

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

## 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]
• a self number in base 10, since there is no integer that added to its own digits adds up to 97.[3]
• 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:

Ninety-seven is:

## References

1. ^ "Sloane's A080076 : Proth primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
2. ^ "Sloane's A005282 : Mian-Chowla sequence". The On-Line Encyclopedia of integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
3. ^ "Sloane's A003052 : Self numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
4. ^ [unicodelookup.com]