320705647 has 2 divisors, whose sum is σ = 320705648. Its totient is φ = 320705646.

The previous prime is 320705621. The next prime is 320705657. The reversal of 320705647 is 746507023.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320705647 is a prime.

It is a super-2 number, since 2×320705647² = 205704224035377218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320705657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160352823 + 160352824.

It is an arithmetic number, because the mean of its divisors is an integer number (160352824).

Almost surely, 2^320705647 is an apocalyptic number.

320705647 is a deficient number, since it is larger than the sum of its proper divisors (1).

320705647 is an equidigital number, since it uses as much as digits as its factorization.

320705647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35280, while the sum is 34.

The square root of 320705647 is about 17908.2563919551. The cubic root of 320705647 is about 684.4927759802.

The spelling of 320705647 in words is "three hundred twenty million, seven hundred five thousand, six hundred forty-seven".