320005681 has 2 divisors, whose sum is σ = 320005682. Its totient is φ = 320005680.

The previous prime is 320005597. The next prime is 320005709. The reversal of 320005681 is 186500023.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 251381025 + 68624656 = 15855^2 + 8284^2 .

It is a cyclic number.

It is not a de Polignac number, because 320005681 - 2²¹ = 317908529 is a prime.

It is a super-2 number, since 2×320005681² = 204807271744547522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (320005181) 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, 160002840 + 160002841.

It is an arithmetic number, because the mean of its divisors is an integer number (160002841).

Almost surely, 2^320005681 is an apocalyptic number.

It is an amenable number.

320005681 is a deficient number, since it is larger than the sum of its proper divisors (1).

320005681 is an equidigital number, since it uses as much as digits as its factorization.

320005681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 320005681 is about 17888.7026080708. The cubic root of 320005681 is about 683.9944263023.

The spelling of 320005681 in words is "three hundred twenty million, five thousand, six hundred eighty-one".