391881 has 8 divisors (see below), whose sum is σ = 597184. Its totient is φ = 223920.

The previous prime is 391879. The next prime is 391889. The reversal of 391881 is 188193.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 391881 - 2¹ = 391879 is a prime.

It is a super-2 number, since 2×391881² = 307141436322, which contains 22 as substring.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391881.

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 7 ways as a sum of consecutive naturals, for example, 9310 + ... + 9351.

It is an arithmetic number, because the mean of its divisors is an integer number (74648).

2³⁹¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

391881 is a deficient number, since it is larger than the sum of its proper divisors (205303).

391881 is a wasteful number, since it uses less digits than its factorization.

391881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18671.

The product of its digits is 1728, while the sum is 30.

The square root of 391881 is about 626.0039935975. The cubic root of 391881 is about 73.1787077132.

The spelling of 391881 in words is "three hundred ninety-one thousand, eight hundred eighty-one".