327991 has 4 divisors (see below), whose sum is σ = 329184. Its totient is φ = 326800.

The previous prime is 327983. The next prime is 328007. The reversal of 327991 is 199723.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 327991 - 2³ = 327983 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 (327941) 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, 51 + ... + 811.

It is an arithmetic number, because the mean of its divisors is an integer number (82296).

2³²⁷⁹⁹¹ is an apocalyptic number.

327991 is a deficient number, since it is larger than the sum of its proper divisors (1193).

327991 is an equidigital number, since it uses as much as digits as its factorization.

327991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1192.

The product of its digits is 3402, while the sum is 31.

The square root of 327991 is about 572.7049851363. The cubic root of 327991 is about 68.9637140304.

The spelling of 327991 in words is "three hundred twenty-seven thousand, nine hundred ninety-one".