Number Gossip
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Unique Properties of 133
- 133 is the smallest number n such that sum of its digits of n equals the least prime dividing n and sum of squares of digits of n equals the greatest prime dividing n
- 133 = 7*19 and pi(133) = pi(7) * pi(19). Note that 133 is the largest composite number with such property
- 133 is the smallest counterbalanced number, that is the smallest composite n for which the sum of the proper divisors of n divides φ(n)