HMMT February

Number theory Difficulty 4.5 AIME Find the answer

What is the smallest positive integer $x$ for which $x^{2}+x+41$ is not a prime?

Your answer

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

40.

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Source: Omni-MATH, licensed Apache-2.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.