Composite Number: 145 is not a prime number; it can be factored into 5×295×29. Divisors: The divisors of 145 are 1, 5, 29, and 145 itself. Deficient Number: The sum of its proper divisors (1 + 5 + 29 = 35) is less than the number itself, categorizing it as a deficient number. Pentagonal Number: It is recognized as a pentagonal number for n=10n=10.