391228 has 12 divisors (see below), whose sum is σ = 699552. Its totient is φ = 191360.

The previous prime is 391219. The next prime is 391231. The reversal of 391228 is 822193.

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 in 3 ways as a sum of consecutive naturals, for example, 853 + ... + 1228.

It is an arithmetic number, because the mean of its divisors is an integer number (58296).

2³⁹¹²²⁸ is an apocalyptic number.

It is an amenable number.

391228 is a deficient number, since it is larger than the sum of its proper divisors (308324).

391228 is a wasteful number, since it uses less digits than its factorization.

391228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132 (or 2130 counting only the distinct ones).

The product of its digits is 864, while the sum is 25.

The square root of 391228 is about 625.4822139757. The cubic root of 391228 is about 73.1380386811.

The spelling of 391228 in words is "three hundred ninety-one thousand, two hundred twenty-eight".