391946 has 4 divisors (see below), whose sum is σ = 587922. Its totient is φ = 195972.

The previous prime is 391939. The next prime is 391961. The reversal of 391946 is 649193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 649193 = 149 ⋅4357.

It can be written as a sum of positive squares in only one way, i.e., 366025 + 25921 = 605^2 + 161^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 97985 + ... + 97988.

2³⁹¹⁹⁴⁶ is an apocalyptic number.

391946 is a deficient number, since it is larger than the sum of its proper divisors (195976).

391946 is a wasteful number, since it uses less digits than its factorization.

391946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195975.

The product of its digits is 5832, while the sum is 32.

The square root of 391946 is about 626.0559080466. The cubic root of 391946 is about 73.1827534593.

The spelling of 391946 in words is "three hundred ninety-one thousand, nine hundred forty-six".