393945871 has 6 divisors (see below), whose sum is σ = 433015016. Its totient is φ = 358132500.

The previous prime is 393945803. The next prime is 393945883. The reversal of 393945871 is 178549393.

It is not a de Polignac number, because 393945871 - 2⁹ = 393945359 is a prime.

It is a super-3 number, since 3×393945871³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393940871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1627755 + ... + 1627996.

Almost surely, 2^393945871 is an apocalyptic number.

393945871 is a deficient number, since it is larger than the sum of its proper divisors (39069145).

393945871 is a wasteful number, since it uses less digits than its factorization.

393945871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3255773 (or 3255762 counting only the distinct ones).

The product of its digits is 816480, while the sum is 49.

The square root of 393945871 is about 19848.0697046337. The cubic root of 393945871 is about 733.0701194253.

The spelling of 393945871 in words is "three hundred ninety-three million, nine hundred forty-five thousand, eight hundred seventy-one".