395991 has 12 divisors (see below), whose sum is σ = 597168. Its totient is φ = 252384.

The previous prime is 395971. The next prime is 396001. The reversal of 395991 is 199593.

It is not a de Polignac number, because 395991 - 2⁵ = 395959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (395921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 750 + ... + 1163.

It is an arithmetic number, because the mean of its divisors is an integer number (49764).

2³⁹⁵⁹⁹¹ is an apocalyptic number.

395991 is a deficient number, since it is larger than the sum of its proper divisors (201177).

395991 is a wasteful number, since it uses less digits than its factorization.

395991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1942 (or 1939 counting only the distinct ones).

The product of its digits is 10935, while the sum is 36.

The square root of 395991 is about 629.2781578920. The cubic root of 395991 is about 73.4336482966.

The spelling of 395991 in words is "three hundred ninety-five thousand, nine hundred ninety-one".