82162079domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes which produce records in A157188, at index i=pi(a(n)) (pi=A000720).at n=24A157190Primes p for which sigma(p+1)/sigma(p) reaches a record value, where sigma(k) is the divisor sum function (A000203).at n=31A326393Prime numbersat n=4788328