391872 has 56 divisors (see below), whose sum is σ = 1123696. Its totient is φ = 119808.

The previous prime is 391861. The next prime is 391873. The reversal of 391872 is 278193.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (391873) by changing a digit.

391872 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, 2418 + ... + 2574.

It is an arithmetic number, because the mean of its divisors is an integer number (20066).

2³⁹¹⁸⁷² is an apocalyptic number.

391872 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (561848).

391872 is an abundant number, since it is smaller than the sum of its proper divisors (731824).

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

391872 is a wasteful number, since it uses less digits than its factorization.

391872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 175 counting only the distinct ones).

The product of its digits is 3024, while the sum is 30.

The square root of 391872 is about 625.9968051037. The cubic root of 391872 is about 73.1781474977.

The spelling of 391872 in words is "three hundred ninety-one thousand, eight hundred seventy-two".