866428064240 has 80 divisors (see below), whose sum is σ = 2134890045792. Its totient is φ = 325886779392.

The previous prime is 866428064237. The next prime is 866428064267. The reversal of 866428064240 is 42460824668.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1201547 + ... + 1782293.

Almost surely, 2^866428064240 is an apocalyptic number.

866428064240 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 866428064240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067445022896).

866428064240 is an abundant number, since it is smaller than the sum of its proper divisors (1268461981552).

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

866428064240 is a wasteful number, since it uses less digits than its factorization.

866428064240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581874 (or 581868 counting only the distinct ones).

The product of its (nonzero) digits is 3538944, while the sum is 50.

The spelling of 866428064240 in words is "eight hundred sixty-six billion, four hundred twenty-eight million, sixty-four thousand, two hundred forty".