391856 has 20 divisors (see below), whose sum is σ = 799800. Its totient is φ = 185472.

The previous prime is 391847. The next prime is 391861. The reversal of 391856 is 658193.

391856 = T₃₈ + T₃₉ + ... + T₁₃₃.

It is a super-2 number, since 2×391856² = 307102249472, which contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391856.

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 3 ways as a sum of consecutive naturals, for example, 341 + ... + 948.

It is an arithmetic number, because the mean of its divisors is an integer number (39990).

2³⁹¹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

391856 is an abundant number, since it is smaller than the sum of its proper divisors (407944).

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

391856 is a wasteful number, since it uses less digits than its factorization.

391856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1316 (or 1310 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 391856 is about 625.9840253553. The cubic root of 391856 is about 73.1771515379.

The spelling of 391856 in words is "three hundred ninety-one thousand, eight hundred fifty-six".