143

This number is a composite.

The last 143 digits of 143¹⁴³ form a prime number. [De Geest]

The smallest number which is bi-prime brilliant in all radices from 2 to 10. [Hartley]

The number of three-digit primes. [Patterson]

100^143 - 143 is prime. Note that 143 is the second number with this property. [Firoozbakht]

The smallest tnaillirb, i.e., a brilliant number whose reversal is a different brilliant number. This is a special subset of emirpimes, with only 102 examples below 100000. [Post]

143² divides 143143. I love you, but now find a prime example like this. [Meller]

The smallest composite number c such that 5^c+2 is prime. [Loungrides]

Coniston Water Lake in the English county of Cumbria has an elevation of 143 feet above sea level.

The number of 3-digit primes is equal to a twin prime pair product (11*13), the addition of whose factors is a factorial: (1*1+1*3)! [Worrom]