391884 has 36 divisors (see below), whose sum is σ = 979944. Its totient is φ = 121856.

The previous prime is 391879. The next prime is 391889. The reversal of 391884 is 488193.

It is an interprime number because it is at equal distance from previous prime (391879) and next prime (391889).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391884.

It is not an unprimeable number, because it can be changed into a prime (391889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3412 + ... + 3524.

2³⁹¹⁸⁸⁴ is an apocalyptic number.

391884 is a gapful number since it is divisible by the number (34) 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 391884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (489972).

391884 is an abundant number, since it is smaller than the sum of its proper divisors (588060).

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

391884 is a wasteful number, since it uses less digits than its factorization.

391884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 135 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

The square root of 391884 is about 626.0063897437. The cubic root of 391884 is about 73.1788944498.

It can be divided in two parts, 391 and 884, that added together give a triangular number (1275 = T₅₀).

The spelling of 391884 in words is "three hundred ninety-one thousand, eight hundred eighty-four".