. . "Pervushin's number"@en . "Pervushin's number is \\(2\\,305\\,843\\,009\\,213\\,693\\,951 = 2^{61}-1\\), the ninth Mersenne prime. It is traditionally denoted as \\(M(61)\\). This number was first proven to be prime by Ivan Mikheevich Pervushin in November of 1883 (hence the designation of Pervushin's number). At the time of its discovery, it was the second largest known prime, holding that position until 1911."@en . . . "Pervushin's number is \\(2\\,305\\,843\\,009\\,213\\,693\\,951 = 2^{61}-1\\), the ninth Mersenne prime. It is traditionally denoted as \\(M(61)\\). This number was first proven to be prime by Ivan Mikheevich Pervushin in November of 1883 (hence the designation of Pervushin's number). At the time of its discovery, it was the second largest known prime, holding that position until 1911."@en .