391812 has 24 divisors (see below), whose sum is σ = 926016. Its totient is φ = 128928.

The previous prime is 391801. The next prime is 391817. The reversal of 391812 is 218193.

391812 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391812.

It is not an unprimeable number, because it can be changed into a prime (391817) by changing a digit.

391812 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 7 ways as a sum of consecutive naturals, for example, 1078 + ... + 1394.

It is an arithmetic number, because the mean of its divisors is an integer number (38584).

2³⁹¹⁸¹² is an apocalyptic number.

It is an amenable number.

391812 is an abundant number, since it is smaller than the sum of its proper divisors (534204).

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

391812 is a wasteful number, since it uses less digits than its factorization.

391812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427 (or 425 counting only the distinct ones).

The product of its digits is 432, while the sum is 24.

The square root of 391812 is about 625.9488797018. The cubic root of 391812 is about 73.1744125086.

The spelling of 391812 in words is "three hundred ninety-one thousand, eight hundred twelve".