321491 has 4 divisors (see below), whose sum is σ = 327000. Its totient is φ = 315984.

The previous prime is 321469. The next prime is 321509. The reversal of 321491 is 194123.

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

It is a cyclic number.

It is not a de Polignac number, because 321491 - 2⁶ = 321427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321091) 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, 2666 + ... + 2783.

It is an arithmetic number, because the mean of its divisors is an integer number (81750).

2³²¹⁴⁹¹ is an apocalyptic number.

321491 is a deficient number, since it is larger than the sum of its proper divisors (5509).

321491 is an equidigital number, since it uses as much as digits as its factorization.

321491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5508.

The product of its digits is 216, while the sum is 20.

The square root of 321491 is about 567.0017636657. The cubic root of 321491 is about 68.5051055565.

The spelling of 321491 in words is "three hundred twenty-one thousand, four hundred ninety-one".