391628 has 12 divisors (see below), whose sum is σ = 721560. Its totient is φ = 185472.

The previous prime is 391627. The next prime is 391631. The reversal of 391628 is 826193.

It is a self number, because there is not a number n which added to its sum of digits gives 391628.

It is not an unprimeable number, because it can be changed into a prime (391627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2501 + ... + 2652.

It is an arithmetic number, because the mean of its divisors is an integer number (60130).

2³⁹¹⁶²⁸ is an apocalyptic number.

391628 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is an amenable number.

391628 is a deficient number, since it is larger than the sum of its proper divisors (329932).

391628 is a wasteful number, since it uses less digits than its factorization.

391628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5176 (or 5174 counting only the distinct ones).

The product of its digits is 2592, while the sum is 29.

The square root of 391628 is about 625.8018855836. The cubic root of 391628 is about 73.1629561638.

The spelling of 391628 in words is "three hundred ninety-one thousand, six hundred twenty-eight".