391908 has 24 divisors (see below), whose sum is σ = 997920. Its totient is φ = 118720.

The previous prime is 391907. The next prime is 391921. The reversal of 391908 is 809193.

It is a happy number.

391908 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (391903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1353 + ... + 1616.

It is an arithmetic number, because the mean of its divisors is an integer number (41580).

2³⁹¹⁹⁰⁸ is an apocalyptic number.

It is an amenable number.

391908 is an abundant number, since it is smaller than the sum of its proper divisors (606012).

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

391908 is a wasteful number, since it uses less digits than its factorization.

391908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2987 (or 2985 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 391908 is about 626.0255585837. The cubic root of 391908 is about 73.1803883082.

The spelling of 391908 in words is "three hundred ninety-one thousand, nine hundred eight".