**149**is a prime number.

**149**and 151 form a pair of twin primes.

**149**has a representation as a sum of two squares:

**149**= 7

^{2}+ 10

^{2}.

**149**is the hypotenuse of a primitive Pythagorean triple:

**149**

^{2}= 51

^{2}+ 140

^{2}.

**149**is the concatenation of the first three positive squares.

**149**is the smallest number whose square starts with three identical digits:

**149**

^{2}= 22201.

**149**is the smallest prime that retains the end (unit) digit of its predecessor (139).

**149**is the smallest number that is the sum of proper substrings of its reverse:

**149**= 1 + 4 + 9 + 94 + 41.

**149**Medusa is an asteroid discovered in 1875.

Source: Number Gossip