A semiprime which English economist and logician William Stanley Jevons incorrectly believed no one else would be able to factor. According
to Jevons (1874, p. 123), "Can the reader say what two numbers multiplied
together will produce the number 8616460799? I think it unlikely that anyone but
myself will ever know."
Actually, a modern computer can factor this number in a few milliseconds as the product of two five-digit numbers:
Published factorizations include those by Lehmer (1903) and Golomb (1996).
Golomb, S. W. "On the Factorization of Jevons' Number." Cryptologia20, 243-244, Jul. 1996.Jevons,
W. S. The
Principles of Science: A Treatise on Logic and Scientific Method. London:
Macmillan, 1874. Reprinted by Kessinger, 2007.Lehmer, D. N. "A
Theorem in the Theory of Numbers." Read before the San Francisco Section of
the American Mathematical Society. Dec. 19, 1903.erovnik,
J. "The RSA Cryptosystem in 1873." Obzornik Mat. Fiz.43,