647238329 has 2 divisors, whose sum is σ = 647238330. Its totient is φ = 647238328.

The previous prime is 647238307. The next prime is 647238337. The reversal of 647238329 is 923832746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643129600 + 4108729 = 25360^2 + 2027^2 .

It is a cyclic number.

It is not a de Polignac number, because 647238329 - 2²⁴ = 630461113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 647238329.

It is not a weakly prime, because it can be changed into another prime (647238379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323619164 + 323619165.

It is an arithmetic number, because the mean of its divisors is an integer number (323619165).

Almost surely, 2^647238329 is an apocalyptic number.

It is an amenable number.

647238329 is a deficient number, since it is larger than the sum of its proper divisors (1).

647238329 is an equidigital number, since it uses as much as digits as its factorization.

647238329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 44.

The square root of 647238329 is about 25440.8790925157. The cubic root of 647238329 is about 865.0105599744.

The spelling of 647238329 in words is "six hundred forty-seven million, two hundred thirty-eight thousand, three hundred twenty-nine".