320785909 has 2 divisors, whose sum is σ = 320785910. Its totient is φ = 320785908.

The previous prime is 320785901. The next prime is 320785921. The reversal of 320785909 is 909587023.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 315169009 + 5616900 = 17753^2 + 2370^2 .

It is a cyclic number.

It is not a de Polignac number, because 320785909 - 2³ = 320785901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320785901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160392954 + 160392955.

It is an arithmetic number, because the mean of its divisors is an integer number (160392955).

Almost surely, 2^320785909 is an apocalyptic number.

It is an amenable number.

320785909 is a deficient number, since it is larger than the sum of its proper divisors (1).

320785909 is an equidigital number, since it uses as much as digits as its factorization.

320785909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 320785909 is about 17910.4971734455. The cubic root of 320785909 is about 684.5498731732.

The spelling of 320785909 in words is "three hundred twenty million, seven hundred eighty-five thousand, nine hundred nine".