331097809 has 4 divisors (see below), whose sum is σ = 378397504. Its totient is φ = 283798116.

The previous prime is 331097803. The next prime is 331097821. The reversal of 331097809 is 908790133.

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, and also an emirpimes, since its reverse is a distinct semiprime: 908790133 = 41 ⋅22165613.

It is not a de Polignac number, because 331097809 - 2⁵ = 331097777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (331097803) 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, 23649837 + ... + 23649850.

It is an arithmetic number, because the mean of its divisors is an integer number (94599376).

Almost surely, 2^331097809 is an apocalyptic number.

It is an amenable number.

331097809 is a deficient number, since it is larger than the sum of its proper divisors (47299695).

331097809 is an equidigital number, since it uses as much as digits as its factorization.

331097809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47299694.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 331097809 is about 18196.0932345380. The cubic root of 331097809 is about 691.8077702606.

The spelling of 331097809 in words is "three hundred thirty-one million, ninety-seven thousand, eight hundred nine".