391577872 has 40 divisors (see below), whose sum is σ = 871472000. Its totient is φ = 166966272.

The previous prime is 391577861. The next prime is 391577891. The reversal of 391577872 is 278775193.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13504 + ... + 31072.

It is an arithmetic number, because the mean of its divisors is an integer number (21786800).

Almost surely, 2^391577872 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 391577872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435736000).

391577872 is an abundant number, since it is smaller than the sum of its proper divisors (479894128).

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

391577872 is a wasteful number, since it uses less digits than its factorization.

391577872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17783 (or 17777 counting only the distinct ones).

The product of its digits is 740880, while the sum is 49.

The square root of 391577872 is about 19788.3266599276. The cubic root of 391577872 is about 731.5983443507.

The spelling of 391577872 in words is "three hundred ninety-one million, five hundred seventy-seven thousand, eight hundred seventy-two".