391664416 has 144 divisors (see below), whose sum is σ = 945955584. Its totient is φ = 158400000.

The previous prime is 391664353. The next prime is 391664417. The reversal of 391664416 is 614466193.

It is not an unprimeable number, because it can be changed into a prime (391664417) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1560291 + ... + 1560541.

It is an arithmetic number, because the mean of its divisors is an integer number (6569136).

Almost surely, 2^391664416 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 391664416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (472977792).

391664416 is an abundant number, since it is smaller than the sum of its proper divisors (554291168).

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

391664416 is a wasteful number, since it uses less digits than its factorization.

391664416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 308 counting only the distinct ones).

The product of its digits is 93312, while the sum is 40.

The square root of 391664416 is about 19790.5132828838. The cubic root of 391664416 is about 731.6522380865.

The spelling of 391664416 in words is "three hundred ninety-one million, six hundred sixty-four thousand, four hundred sixteen".