5207819

Appears in sequences

• Numbers of the form p*q, where p is prime and q=(p^k-1)/(p-1) is also prime for some integer k>1.at n=23A330832
• Nonprime-powers k such that, for any prime p dividing k and m = 1+floor(log k/log p), rad(p^m (mod k)) divides k, where rad = A007947.at n=32A381750
• Numbers k in A024619 such that all residues r (mod k) in row k of A381801 are such that rad(r) divides k, where rad = A007947.at n=25A382438