149 is the 35th
prime number, the first prime whose difference from the previous prime is exactly 10,[1] an
emirp, and an
irregular prime.[2] After 1 and 127, it is the third smallest
de Polignac number, an odd number that cannot be represented as a prime plus a
power of two.[3] More strongly, after 1, it is the second smallest number that is not a sum of two
prime powers.[4]
It is a
tribonacci number, being the sum of the three preceding terms, 24, 44, 81.[5]
There are exactly 149 integer points in a closed circular disk of radius 7,[6] and exactly 149 ways of placing six queens (the maximum possible) on a 5 × 5 chess board so that each queen attacks exactly one other.[7] The
barycentric subdivision of a
tetrahedron produces an
abstract simplicial complex with exactly 149 simplices.[8]