394505664 has 168 divisors, whose sum is σ = 1278696960. Its totient is φ = 106735104.

The previous prime is 394505653. The next prime is 394505701. The reversal of 394505664 is 466505493.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 177649 + ... + 179855.

Almost surely, 2^394505664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 394505664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (639348480).

394505664 is an abundant number, since it is smaller than the sum of its proper divisors (884191296).

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

394505664 is a wasteful number, since it uses less digits than its factorization.

394505664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2255 (or 2238 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The square root of 394505664 is about 19862.1666491851. The cubic root of 394505664 is about 733.4171834332.

The spelling of 394505664 in words is "three hundred ninety-four million, five hundred five thousand, six hundred sixty-four".