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
202 (number) 202 (number) 202 (two hundred [and] two) is the natural number following 201 and preceding 203. 202 is a Smith number, meaning that its digit sum and the sum of digits of its prime factors are equal. It is also a strobogrammatic number, meaning that when shown on a seven-segment display, turning the display upside-down shows the same number. There are exactly 202 partitions of 32 (a power of two) into smaller powers of two. There are also 202 distinct (non-congruent) polygons that can be formed by connecting all eight vertices of a regular octagon into a cycle, and 202