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Ten prime-digit numbers with digit product 100000

Question

Count the ten-digit numbers in which every digit is a prime number and the product of all ten digits equals 100000100000.

Short answer

252252. Since 100000=25⋅55100000=2^5\cdot5^5, the digits can only be 22s and 55s, with five of each to use all ten places. Choosing which five positions hold the 22s gives (105)=252\binom{10}{5}=252.

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