320821873 has 2 divisors, whose sum is σ = 320821874. Its totient is φ = 320821872.

The previous prime is 320821817. The next prime is 320821877. The reversal of 320821873 is 378128023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 317089249 + 3732624 = 17807^2 + 1932^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320821873 is a prime.

It is not a weakly prime, because it can be changed into another prime (320821877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160410936 + 160410937.

It is an arithmetic number, because the mean of its divisors is an integer number (160410937).

Almost surely, 2^320821873 is an apocalyptic number.

It is an amenable number.

320821873 is a deficient number, since it is larger than the sum of its proper divisors (1).

320821873 is an equidigital number, since it uses as much as digits as its factorization.

320821873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 320821873 is about 17911.5011375373. The cubic root of 320821873 is about 684.5754543381.

Adding to 320821873 its reverse (378128023), we get a palindrome (698949896).

The spelling of 320821873 in words is "three hundred twenty million, eight hundred twenty-one thousand, eight hundred seventy-three".