331640009 has 2 divisors, whose sum is σ = 331640010. Its totient is φ = 331640008.

The previous prime is 331639937. The next prime is 331640039. The reversal of 331640009 is 900046133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237006025 + 94633984 = 15395^2 + 9728^2 .

It is a cyclic number.

It is not a de Polignac number, because 331640009 - 2⁸ = 331639753 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 331640009.

It is not a weakly prime, because it can be changed into another prime (331640039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165820004 + 165820005.

It is an arithmetic number, because the mean of its divisors is an integer number (165820005).

Almost surely, 2^331640009 is an apocalyptic number.

It is an amenable number.

331640009 is a deficient number, since it is larger than the sum of its proper divisors (1).

331640009 is an equidigital number, since it uses as much as digits as its factorization.

331640009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 331640009 is about 18210.9859425568. The cubic root of 331640009 is about 692.1851950955.

The spelling of 331640009 in words is "three hundred thirty-one million, six hundred forty thousand, nine".