79 (number) - in Mathematics

In Mathematics

• An odd number
• The smallest number that can't be represented as a sum of fewer than 19 fourth powers
• A strictly non-palindromic number
• The 22nd prime number (the next is 83)
• The smallest prime number p for which the real quadratic field Q has class number greater than 1 (namely 3)
• A cousin prime with 83
• An emirp, because the reverse of 79, 97, is also a prime
• A fortunate prime
• A prime number that is also a Gaussian prime (since it is of the form )
• A happy prime
• A Higgs prime
• A Kynea prime
• A lucky prime
• A permutable prime, with ninety-seven
• A Pillai prime, because 23! + 1 is divisible by 79, but 79 is not one more than a multiple of 23
• A regular prime
• A prime in a residue classes 4n+3, 8n+7, and 10n+9
• A right-truncatable prime, because when the last digit (9) is removed, the remaining number (7) is still prime
• A sexy prime (with 73)
• The n value of the Wagstaff prime 201487636602438195784363