865099816812 has 480 divisors, whose sum is σ = 2907291695616. Its totient is φ = 217783987200.

The previous prime is 865099816751. The next prime is 865099816849. The reversal of 865099816812 is 218618990568.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a self number, because there is not a number n which added to its sum of digits gives 865099816812.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 160587583 + ... + 160592969.

Almost surely, 2^865099816812 is an apocalyptic number.

865099816812 is a gapful number since it is divisible by the number (82) 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 865099816812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1453645847808).

865099816812 is an abundant number, since it is smaller than the sum of its proper divisors (2042191878804).

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

865099816812 is a wasteful number, since it uses less digits than its factorization.

865099816812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5619 (or 5608 counting only the distinct ones).

The product of its (nonzero) digits is 14929920, while the sum is 63.

The spelling of 865099816812 in words is "eight hundred sixty-five billion, ninety-nine million, eight hundred sixteen thousand, eight hundred twelve".