320242561 has 2 divisors, whose sum is σ = 320242562. Its totient is φ = 320242560.

The previous prime is 320242499. The next prime is 320242579. The reversal of 320242561 is 165242023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179962225 + 140280336 = 13415^2 + 11844^2 .

It is a cyclic number.

It is not a de Polignac number, because 320242561 - 2²¹ = 318145409 is a prime.

It is not a weakly prime, because it can be changed into another prime (320242591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160121280 + 160121281.

It is an arithmetic number, because the mean of its divisors is an integer number (160121281).

Almost surely, 2^320242561 is an apocalyptic number.

It is an amenable number.

320242561 is a deficient number, since it is larger than the sum of its proper divisors (1).

320242561 is an equidigital number, since it uses as much as digits as its factorization.

320242561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 320242561 is about 17895.3223217689. The cubic root of 320242561 is about 684.1631573039.

Adding to 320242561 its reverse (165242023), we get a palindrome (485484584).

The spelling of 320242561 in words is "three hundred twenty million, two hundred forty-two thousand, five hundred sixty-one".