331220009 has 2 divisors, whose sum is σ = 331220010. Its totient is φ = 331220008.

The previous prime is 331219979. The next prime is 331220023. The reversal of 331220009 is 900022133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 306250000 + 24970009 = 17500^2 + 4997^2 .

It is a cyclic number.

It is not a de Polignac number, because 331220009 - 2⁸ = 331219753 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (331220059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165610004 + 165610005.

It is an arithmetic number, because the mean of its divisors is an integer number (165610005).

Almost surely, 2^331220009 is an apocalyptic number.

It is an amenable number.

331220009 is a deficient number, since it is larger than the sum of its proper divisors (1).

331220009 is an equidigital number, since it uses as much as digits as its factorization.

331220009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 331220009 is about 18199.4507884167. The cubic root of 331220009 is about 691.8928694961.

The spelling of 331220009 in words is "three hundred thirty-one million, two hundred twenty thousand, nine".