65581020521220 has 48 divisors (see below), whose sum is σ = 184358438607168. Its totient is φ = 17418597744000.

The previous prime is 65581020521179. The next prime is 65581020521267. The reversal of 65581020521220 is 2212502018556.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2177309659 + ... + 2177339778.

It is an arithmetic number, because the mean of its divisors is an integer number (3840800804316).

Almost surely, 2^{65581020521220} is an apocalyptic number.

65581020521220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65581020521220 is an abundant number, since it is smaller than the sum of its proper divisors (118777418085948).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65581020521220 is a wasteful number, since it uses less digits than its factorization.

65581020521220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4354649700 (or 4354649698 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 39.

Adding to 65581020521220 its reverse (2212502018556), we get a palindrome (67793522539776).

The spelling of 65581020521220 in words is "sixty-five trillion, five hundred eighty-one billion, twenty million, five hundred twenty-one thousand, two hundred twenty".