394668769840 has 80 divisors (see below), whose sum is σ = 957848336640. Its totient is φ = 151058350080.

The previous prime is 394668769819. The next prime is 394668769867. The reversal of 394668769840 is 48967866493.

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

It is a self number, because there is not a number n which added to its sum of digits gives 394668769840.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 673329 + ... + 1114768.

It is an arithmetic number, because the mean of its divisors is an integer number (11973104208).

Almost surely, 2^394668769840 is an apocalyptic number.

It is an amenable number.

394668769840 is an abundant number, since it is smaller than the sum of its proper divisors (563179566800).

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

394668769840 is a wasteful number, since it uses less digits than its factorization.

394668769840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788230 (or 1788224 counting only the distinct ones).

The product of its (nonzero) digits is 376233984, while the sum is 70.

The spelling of 394668769840 in words is "three hundred ninety-four billion, six hundred sixty-eight million, seven hundred sixty-nine thousand, eight hundred forty".