394390682778 has 8 divisors (see below), whose sum is σ = 788781365568. Its totient is φ = 131463560924.

The previous prime is 394390682731. The next prime is 394390682801. The reversal of 394390682778 is 877286093493.

394390682778 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

394390682778 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32865890226 + ... + 32865890237.

It is an arithmetic number, because the mean of its divisors is an integer number (98597670696).

Almost surely, 2^394390682778 is an apocalyptic number.

394390682778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

394390682778 is a wasteful number, since it uses less digits than its factorization.

394390682778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65731780468.

The product of its (nonzero) digits is 109734912, while the sum is 66.

The spelling of 394390682778 in words is "three hundred ninety-four billion, three hundred ninety million, six hundred eighty-two thousand, seven hundred seventy-eight".