866786278586440 has 64 divisors (see below), whose sum is σ = 1992665882937600. Its totient is φ = 339337605310144.

The previous prime is 866786278586399. The next prime is 866786278586441. The reversal of 866786278586440 is 44685872687668.

It is not an unprimeable number, because it can be changed into a prime (866786278586441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100205734 + ... + 108511573.

It is an arithmetic number, because the mean of its divisors is an integer number (31135404420900).

Almost surely, 2^{866786278586440} is an apocalyptic number.

It is an amenable number.

866786278586440 is an abundant number, since it is smaller than the sum of its proper divisors (1125879604351160).

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

866786278586440 is an equidigital number, since it uses as much as digits as its factorization.

866786278586440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208717459 (or 208717361 counting only the distinct ones).

The product of its (nonzero) digits is 41617981440, while the sum is 85.

The spelling of 866786278586440 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred seventy-eight million, five hundred eighty-six thousand, four hundred forty".