394476992640 has 384 divisors, whose sum is σ = 1391860033200. Its totient is φ = 102926647296.

The previous prime is 394476992629. The next prime is 394476992647. The reversal of 394476992640 is 46299674493.

394476992640 is a `hidden beast` number, since 3 + 9 + 447 + 69 + 92 + 6 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 63226096704 + 331250895936 = 251448^2 + 575544^2 .

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×394476992640² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (394476992647) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 49722114 + ... + 49730046.

Almost surely, 2^394476992640 is an apocalyptic number.

394476992640 is a gapful number since it is divisible by the number (30) 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 394476992640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (695930016600).

394476992640 is an abundant number, since it is smaller than the sum of its proper divisors (997383040560).

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

394476992640 is a wasteful number, since it uses less digits than its factorization.

394476992640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8144 (or 8129 counting only the distinct ones).

The product of its (nonzero) digits is 70543872, while the sum is 63.

The spelling of 394476992640 in words is "three hundred ninety-four billion, four hundred seventy-six million, nine hundred ninety-two thousand, six hundred forty".