331091 has 4 divisors (see below), whose sum is σ = 337392. Its totient is φ = 324792.

The previous prime is 331081. The next prime is 331099. The reversal of 331091 is 190133.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190133 = 19 ⋅10007.

It is a cyclic number.

It is not a de Polignac number, because 331091 - 2⁶ = 331027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (331099) 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, 3071 + ... + 3176.

It is an arithmetic number, because the mean of its divisors is an integer number (84348).

2³³¹⁰⁹¹ is an apocalyptic number.

331091 is a deficient number, since it is larger than the sum of its proper divisors (6301).

331091 is an equidigital number, since it uses as much as digits as its factorization.

331091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6300.

The product of its (nonzero) digits is 81, while the sum is 17.

The square root of 331091 is about 575.4050747082. The cubic root of 331091 is about 69.1803027904.

The spelling of 331091 in words is "three hundred thirty-one thousand, ninety-one".