391880 has 32 divisors (see below), whose sum is σ = 899640. Its totient is φ = 153600.

The previous prime is 391879. The next prime is 391889. The reversal of 391880 is 88193.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 376996 + 14884 = 614^2 + 122^2 .

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3830 + ... + 3930.

2³⁹¹⁸⁸⁰ is an apocalyptic number.

It is an amenable number.

391880 is an abundant number, since it is smaller than the sum of its proper divisors (507760).

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

391880 is a wasteful number, since it uses less digits than its factorization.

391880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 391880 is about 626.0031948800. The cubic root of 391880 is about 73.1786454675.

The spelling of 391880 in words is "three hundred ninety-one thousand, eight hundred eighty".