320065981 has 2 divisors, whose sum is σ = 320065982. Its totient is φ = 320065980.

The previous prime is 320065937. The next prime is 320066017. The reversal of 320065981 is 189560023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 272580100 + 47485881 = 16510^2 + 6891^2 .

It is a cyclic number.

It is not a de Polignac number, because 320065981 - 2⁷ = 320065853 is a prime.

It is a super-2 number, since 2×320065981² = 204884464386984722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320095981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160032990 + 160032991.

It is an arithmetic number, because the mean of its divisors is an integer number (160032991).

Almost surely, 2^320065981 is an apocalyptic number.

It is an amenable number.

320065981 is a deficient number, since it is larger than the sum of its proper divisors (1).

320065981 is an equidigital number, since it uses as much as digits as its factorization.

320065981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 320065981 is about 17890.3879499579. The cubic root of 320065981 is about 684.0373862412.

The spelling of 320065981 in words is "three hundred twenty million, sixty-five thousand, nine hundred eighty-one".