866186687438040 has 128 divisors (see below), whose sum is σ = 2642634753696000. Its totient is φ = 227065459051008.

The previous prime is 866186687438029. The next prime is 866186687438041. The reversal of 866186687438040 is 40834786681668.

866186687438040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (75) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866186687438041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 636654982 + ... + 638014058.

It is an arithmetic number, because the mean of its divisors is an integer number (20645584013250).

Almost surely, 2^{866186687438040} is an apocalyptic number.

It is an amenable number.

866186687438040 is an abundant number, since it is smaller than the sum of its proper divisors (1776448066257960).

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

866186687438040 is a wasteful number, since it uses less digits than its factorization.

866186687438040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1449169 (or 1449165 counting only the distinct ones).

The product of its (nonzero) digits is 1783627776, while the sum is 75.

The spelling of 866186687438040 in words is "eight hundred sixty-six trillion, one hundred eighty-six billion, six hundred eighty-seven million, four hundred thirty-eight thousand, forty".