331309 has 4 divisors (see below), whose sum is σ = 361440. Its totient is φ = 301180.

The previous prime is 331307. The next prime is 331319. The reversal of 331309 is 903133.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 331309 - 2¹ = 331307 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331301) 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, 15049 + ... + 15070.

It is an arithmetic number, because the mean of its divisors is an integer number (90360).

2³³¹³⁰⁹ is an apocalyptic number.

It is an amenable number.

331309 is a deficient number, since it is larger than the sum of its proper divisors (30131).

331309 is a wasteful number, since it uses less digits than its factorization.

331309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30130.

The product of its (nonzero) digits is 243, while the sum is 19.

The square root of 331309 is about 575.5944753036. The cubic root of 331309 is about 69.1954829043.

The spelling of 331309 in words is "three hundred thirty-one thousand, three hundred nine".