865808867520 has 168 divisors, whose sum is σ = 2993615389440. Its totient is φ = 229673410560.

The previous prime is 865808867501. The next prime is 865808867527. The reversal of 865808867520 is 25768808568.

It is not an unprimeable number, because it can be changed into a prime (865808867527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 236905 + ... + 1337064.

Almost surely, 2^865808867520 is an apocalyptic number.

865808867520 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 865808867520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1496807694720).

865808867520 is an abundant number, since it is smaller than the sum of its proper divisors (2127806521920).

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

865808867520 is a wasteful number, since it uses less digits than its factorization.

865808867520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1574183 (or 1574170 counting only the distinct ones).

The product of its (nonzero) digits is 51609600, while the sum is 63.

The spelling of 865808867520 in words is "eight hundred sixty-five billion, eight hundred eight million, eight hundred sixty-seven thousand, five hundred twenty".