321891 has 8 divisors (see below), whose sum is σ = 439824. Its totient is φ = 209280.

The previous prime is 321889. The next prime is 321901. The reversal of 321891 is 198123.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 321891 - 2¹ = 321889 is a prime.

It is a super-2 number, since 2×321891² = 207227631762, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (321821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1186 + ... + 1431.

It is an arithmetic number, because the mean of its divisors is an integer number (54978).

2³²¹⁸⁹¹ is an apocalyptic number.

321891 is a deficient number, since it is larger than the sum of its proper divisors (117933).

321891 is a wasteful number, since it uses less digits than its factorization.

321891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2661.

The product of its digits is 432, while the sum is 24.

The square root of 321891 is about 567.3543866051. The cubic root of 321891 is about 68.5335051960.

The spelling of 321891 in words is "three hundred twenty-one thousand, eight hundred ninety-one".