5525519domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes of the form A128646(k)-1 for some k (listed in A137689), where A128646 = denominators of partial sums of 1/(prime(i)-1).at n=8A137690Safe primes that are also highly cototient numbers.at n=22A209193Prime numbersat n=382421