321091 has 2 divisors, whose sum is σ = 321092. Its totient is φ = 321090.

The previous prime is 321077. The next prime is 321109. The reversal of 321091 is 190123.

Together with next prime (321109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 321091 - 2¹³ = 312899 is a prime.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (321031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160545 + 160546.

It is an arithmetic number, because the mean of its divisors is an integer number (160546).

2³²¹⁰⁹¹ is an apocalyptic number.

321091 is a deficient number, since it is larger than the sum of its proper divisors (1).

321091 is an equidigital number, since it uses as much as digits as its factorization.

321091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 321091 is about 566.6489212908. The cubic root of 321091 is about 68.4766823507.

The spelling of 321091 in words is "three hundred twenty-one thousand, ninety-one".