I’ve been looking for whole numbers ‘n’ for whichthe sum of divisors function sigma(n) has a valuethat is “extremely large” relative to n. It can be shown that: limsup n→∞ σ(n)/[n log(log(n)) ] = e^gamma . (Grönwall, 1913) where sigma(n) is the sum of all divisors of the positive integer n. I got a 12,025-digit… Continue reading About a 12025-digit “highly composite” number called “a4”