85636720640 has 144 divisors (see below), whose sum is σ = 214813790100. Its totient is φ = 32763281408.

The previous prime is 85636720613. The next prime is 85636720657. The reversal of 85636720640 is 4602763658.

It can be written as a sum of positive squares in 2 ways, for example, as 74559579136 + 11077141504 = 273056^2 + 105248^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5409056 + ... + 5424864.

Almost surely, 2^85636720640 is an apocalyptic number.

85636720640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 85636720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107406895050).

85636720640 is an abundant number, since it is smaller than the sum of its proper divisors (129177069460).

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

85636720640 is a wasteful number, since it uses less digits than its factorization.

85636720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15882 (or 15839 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 47.

The spelling of 85636720640 in words is "eighty-five billion, six hundred thirty-six million, seven hundred twenty thousand, six hundred forty".