391943 has 4 divisors (see below), whose sum is σ = 409008. Its totient is φ = 374880.

The previous prime is 391939. The next prime is 391961. The reversal of 391943 is 349193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 349193 = 13 ⋅26861.

It is a cyclic number.

It is not a de Polignac number, because 391943 - 2² = 391939 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8498 + ... + 8543.

It is an arithmetic number, because the mean of its divisors is an integer number (102252).

2³⁹¹⁹⁴³ is an apocalyptic number.

391943 is a deficient number, since it is larger than the sum of its proper divisors (17065).

391943 is a wasteful number, since it uses less digits than its factorization.

391943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17064.

The product of its digits is 2916, while the sum is 29.

The square root of 391943 is about 626.0535120898. The cubic root of 391943 is about 73.1825667424.

The spelling of 391943 in words is "three hundred ninety-one thousand, nine hundred forty-three".