391924 has 12 divisors (see below), whose sum is σ = 738724. Its totient is φ = 180864.

The previous prime is 391921. The next prime is 391939. The reversal of 391924 is 429193.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 108900 + 283024 = 330^2 + 532^2 .

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a plaindrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 391892 and 391901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3717 + ... + 3820.

2³⁹¹⁹²⁴ is an apocalyptic number.

It is an amenable number.

391924 is a deficient number, since it is larger than the sum of its proper divisors (346800).

391924 is a wasteful number, since it uses less digits than its factorization.

391924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7554 (or 7552 counting only the distinct ones).

The product of its digits is 1944, while the sum is 28.

The square root of 391924 is about 626.0383374842. The cubic root of 391924 is about 73.1813841799.

The spelling of 391924 in words is "three hundred ninety-one thousand, nine hundred twenty-four".