Persistence of a number assumed. The single-digit final state reached in the process of calculating an integer's additive persistence is its digital root. Put another way, a number's additive persistence counts how many times we must sum its digits to arrive at its digital root. The additive persistence of 2718 is 2: first we find that 2 + 7 + 1 + 8 = 18, and then that 1 + 8 = 9. The multiplicative persistence of 39 is 3, because it takes three steps to reduce 39 to a single digit: 39 → 27 → 14 → 4. Also, 39 is the smallest
132 (number) 132 is a self number. 132 is also a Harshad number, divisible by the sum of its base-ten digits. 132 is also: 132 (number) 132 (one hundred [and] thirty-two) is the natural number following 131 and preceding 133. 132 is the sixth Catalan number. It is a pronic number, the product of 11 and 12. As it has 12 divisors total, 132 is a refactorable number. If you take the sum of all 2-digit numbers you can make from 132, you get 132: formula_1. 132 is the smallest number with this property, which is shared by 264, 396 and 35964