391946943 has 4 divisors (see below), whose sum is σ = 522595928. Its totient is φ = 261297960.

The previous prime is 391946939. The next prime is 391946983. The reversal of 391946943 is 349649193.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 391946943 - 2² = 391946939 is a prime.

It is a super-2 number, since 2×391946943² = 307244812254090498, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 391946892 and 391946901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391946983) 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, 65324488 + ... + 65324493.

It is an arithmetic number, because the mean of its divisors is an integer number (130648982).

Almost surely, 2^391946943 is an apocalyptic number.

391946943 is a deficient number, since it is larger than the sum of its proper divisors (130648985).

391946943 is a wasteful number, since it uses less digits than its factorization.

391946943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130648984.

The product of its digits is 629856, while the sum is 48.

The square root of 391946943 is about 19797.6499362929. The cubic root of 391946943 is about 731.8281215041.

The spelling of 391946943 in words is "three hundred ninety-one million, nine hundred forty-six thousand, nine hundred forty-three".