320807813 has 2 divisors, whose sum is σ = 320807814. Its totient is φ = 320807812.

The previous prime is 320807807. The next prime is 320807849. The reversal of 320807813 is 318708023.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 247842049 + 72965764 = 15743^2 + 8542^2 .

It is an emirp because it is prime and its reverse (318708023) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320807813 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_17316545 and since 320807813 and 17316545 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 320807813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320807803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160403906 + 160403907.

It is an arithmetic number, because the mean of its divisors is an integer number (160403907).

Almost surely, 2^320807813 is an apocalyptic number.

It is an amenable number.

320807813 is a deficient number, since it is larger than the sum of its proper divisors (1).

320807813 is an equidigital number, since it uses as much as digits as its factorization.

320807813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 320807813 is about 17911.1086479871. The cubic root of 320807813 is about 684.5654536988.

It can be divided in two parts, 32080 and 7813, that added together give a palindrome (39893).

The spelling of 320807813 in words is "three hundred twenty million, eight hundred seven thousand, eight hundred thirteen".