391312 has 20 divisors (see below), whose sum is σ = 779836. Its totient is φ = 190080.

The previous prime is 391301. The next prime is 391331. The reversal of 391312 is 213193.

391312 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 331776 + 59536 = 576^2 + 244^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 391312.

It is an unprimeable number.

391312 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262 + ... + 922.

2³⁹¹³¹² is an apocalyptic number.

It is an amenable number.

391312 is a deficient number, since it is larger than the sum of its proper divisors (388524).

391312 is a wasteful number, since it uses less digits than its factorization.

391312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706 (or 700 counting only the distinct ones).

The product of its digits is 162, while the sum is 19.

The square root of 391312 is about 625.5493585641. The cubic root of 391312 is about 73.1432727608.

It can be divided in two parts, 391 and 312, that added together give a triangular number (703 = T₃₇).

The spelling of 391312 in words is "three hundred ninety-one thousand, three hundred twelve".