6666878394 has 128 divisors (see below), whose sum is σ = 17057433600. Its totient is φ = 1910367360.

The previous prime is 6666878363. The next prime is 6666878447. The reversal of 6666878394 is 4938786666.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1213177 + ... + 1218659.

It is an arithmetic number, because the mean of its divisors is an integer number (133261200).

Almost surely, 2^6666878394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6666878394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8528716800).

6666878394 is an abundant number, since it is smaller than the sum of its proper divisors (10390555206).

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

6666878394 is a wasteful number, since it uses less digits than its factorization.

6666878394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5617 (or 5611 counting only the distinct ones).

The product of its digits is 62705664, while the sum is 63.

The square root of 6666878394 is about 81650.9546423065. The cubic root of 6666878394 is about 1882.0919818560.

The spelling of 6666878394 in words is "six billion, six hundred sixty-six million, eight hundred seventy-eight thousand, three hundred ninety-four".