35
(another Prime Pages' Curiosity)
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+ The number of pairs of twin primes less than 1000.

+ The first composite number occurring in Pascal's Triangle whose digit reversal is prime.

+ The product of 35 and 36 has the same prime factors as the product of 4374 and 4375. [Guy]

+ 35 is the smallest product of Twin primes of the form (4*k+1, 4*k+3), k>0. [Zumkeller]

+ The number of known even numbers which are not the sum of two twin primes (coming from the same pair or not). [Capelle]

+ 35 can be written as a sum of odd primes in 35 ways, and as a sum of primes in 35 * 5 ways. [Hartley]

+ 35 = 23 + 33, i.e., the sum of the cubes of the first two primes. [Mizuki]

+ 35 is the smallest number formed from two odd primes. It's prime factors are 5 and 7. Note that its digital sum (8) and digital product (15) are each one less than perfect squares. No prime number greater than 3 fits this category. [Storms]

+ 5*7 = (29+41)/2 is a 2-almost prime (biprime) formed by 2nd twin prime couple and also arithmetic mean of 2 consecutive lesser primes of two twin prime couples. Much MORE: (a) (p,q) = (5,7) and (29,41) are the first two consecutive prime solutions of Diophantine equation 2*p^2 = 1+q^2, (b) (p*q)^2 = q^2*(q^2+1)/2, i.e., triangular number T(q^2) a square, (c) p^2 = [(q-1)/2)]^2+[(q+1)/2]^2, i.e., two Pythagorean triples (a,b,c) with a prime hypotenuse c = p and two legs a, b which differ just by 1: b-a = (q+1)/2-(q-1)/2=1. [Krug]




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