7,999,973 not a prime, is a composite number.
7,999,973 = 197 × 40,609;
Explanations below.

40,609 is a prime number, it cannot be prime factorized into other prime factors;
Explanations below.

Positive integers that are only dividing by themselves and 1 are called
prime numbers. A composite number is a positive integer that has at
least one factor (divisor) other than 1 and itself.