# 263 (number)

 ← 262 263 264 →
Cardinal two hundred sixty-three
Ordinal 263rd
(two hundred sixty-third)
Factorization prime
Prime yes
Greek numeral ΣΞΓ´
Roman numeral CCLXIII
Binary 1000001112
Ternary 1002023
Quaternary 100134
Quinary 20235
Senary 11156
Octal 4078
Duodecimal 19B12
Vigesimal D320
Base 36 7B36

263 is the natural number between 262 and 264. It is also a prime number.

## In mathematics

263 is a balanced prime,[1] an irregular prime,[2] a Ramanujan prime,[3] a Chen prime,[4] and a safe prime.[5]

It is also a strictly non-palindromic number and a happy number.[6]

## References

1. ^ Sloane, N.J.A. (ed.). "Sequence A006562 (Balanced primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
2. ^ Sloane, N.J.A. (ed.). "Sequence A000928 (Irregular primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
3. ^ Sloane, N.J.A. (ed.). "Sequence A104272 (Ramanujan primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
4. ^ "Sloane's A109611 : Chen primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-04-21.
5. ^ Sloane, N.J.A. (ed.). "Sequence A005385 (Safe primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
6. ^ "Sloane's A007770 : Happy numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-04-21.