320631345361721 has 2 divisors, whose sum is σ = 320631345361722. Its totient is φ = 320631345361720.

The previous prime is 320631345361687. The next prime is 320631345361739. The reversal of 320631345361721 is 127163543136023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 262632458871721 + 57998886490000 = 16205939^2 + 7615700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320631345361721 is a prime.

It is not a weakly prime, because it can be changed into another prime (320631348361721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160315672680860 + 160315672680861.

It is an arithmetic number, because the mean of its divisors is an integer number (160315672680861).

Almost surely, 2^{320631345361721} is an apocalyptic number.

It is an amenable number.

320631345361721 is a deficient number, since it is larger than the sum of its proper divisors (1).

320631345361721 is an equidigital number, since it uses as much as digits as its factorization.

320631345361721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1632960, while the sum is 47.

Adding to 320631345361721 its reverse (127163543136023), we get a palindrome (447794888497744).

The spelling of 320631345361721 in words is "three hundred twenty trillion, six hundred thirty-one billion, three hundred forty-five million, three hundred sixty-one thousand, seven hundred twenty-one".