391940 has 12 divisors (see below), whose sum is σ = 823116. Its totient is φ = 156768.

The previous prime is 391939. The next prime is 391961. The reversal of 391940 is 49193.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 145924 + 246016 = 382^2 + 496^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9779 + ... + 9818.

It is an arithmetic number, because the mean of its divisors is an integer number (68593).

2³⁹¹⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

391940 is an abundant number, since it is smaller than the sum of its proper divisors (431176).

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

391940 is a wasteful number, since it uses less digits than its factorization.

391940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19606 (or 19604 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 391940 is about 626.0511161239. The cubic root of 391940 is about 73.1823800245.

It can be divided in two parts, 391 and 940, that added together give a palindrome (1331).

The spelling of 391940 in words is "three hundred ninety-one thousand, nine hundred forty".