391318 has 4 divisors (see below), whose sum is σ = 586980. Its totient is φ = 195658.

The previous prime is 391301. The next prime is 391331. The reversal of 391318 is 813193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 813193 = 89 ⋅9137.

It is a junction number, because it is equal to n+sod(n) for n = 391292 and 391301.

It is a congruent 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 as a sum of consecutive naturals, namely, 97828 + ... + 97831.

It is an arithmetic number, because the mean of its divisors is an integer number (146745).

2³⁹¹³¹⁸ is an apocalyptic number.

391318 is a deficient number, since it is larger than the sum of its proper divisors (195662).

391318 is a wasteful number, since it uses less digits than its factorization.

391318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195661.

The product of its digits is 648, while the sum is 25.

The square root of 391318 is about 625.5541543304. The cubic root of 391318 is about 73.1436465950.

Subtracting 391318 from its reverse (813193), we obtain a cube (421875 = 75³).

The spelling of 391318 in words is "three hundred ninety-one thousand, three hundred eighteen".