865505841045720 has 512 divisors, whose sum is σ = 3028943949004800. Its totient is φ = 193770720460800.

The previous prime is 865505841045697. The next prime is 865505841045757. The reversal of 865505841045720 is 27540148505568.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5809040425 + ... + 5809189415.

It is an arithmetic number, because the mean of its divisors is an integer number (5915906150400).

Almost surely, 2^{865505841045720} 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 865505841045720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1514471974502400).

865505841045720 is an abundant number, since it is smaller than the sum of its proper divisors (2163438107959080).

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

865505841045720 is a wasteful number, since it uses less digits than its factorization.

865505841045720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149719 (or 149715 counting only the distinct ones).

The product of its (nonzero) digits is 53760000, while the sum is 60.

The spelling of 865505841045720 in words is "eight hundred sixty-five trillion, five hundred five billion, eight hundred forty-one million, forty-five thousand, seven hundred twenty".