65205217720 has 64 divisors (see below), whose sum is σ = 151668080640. Its totient is φ = 25203446400.

The previous prime is 65205217709. The next prime is 65205217733. The reversal of 65205217720 is 2771250256.

65205217720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 65205217720.

It is a congruent 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, 808425 + ... + 885415.

It is an arithmetic number, because the mean of its divisors is an integer number (2369813760).

Almost surely, 2^65205217720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65205217720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75834040320).

65205217720 is an abundant number, since it is smaller than the sum of its proper divisors (86462862920).

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

65205217720 is a wasteful number, since it uses less digits than its factorization.

65205217720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77716 (or 77712 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 37.

Adding to 65205217720 its reverse (2771250256), we get a palindrome (67976467976).

The spelling of 65205217720 in words is "sixty-five billion, two hundred five million, two hundred seventeen thousand, seven hundred twenty".