647364217 has 2 divisors, whose sum is σ = 647364218. Its totient is φ = 647364216.

The previous prime is 647364209. The next prime is 647364259. The reversal of 647364217 is 712463746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 466084921 + 181279296 = 21589^2 + 13464^2 .

It is a cyclic number.

It is not a de Polignac number, because 647364217 - 2³ = 647364209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 647364217.

It is not a weakly prime, because it can be changed into another prime (647364917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323682108 + 323682109.

It is an arithmetic number, because the mean of its divisors is an integer number (323682109).

Almost surely, 2^647364217 is an apocalyptic number.

It is an amenable number.

647364217 is a deficient number, since it is larger than the sum of its proper divisors (1).

647364217 is an equidigital number, since it uses as much as digits as its factorization.

647364217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 40.

The square root of 647364217 is about 25443.3531005644. The cubic root of 647364217 is about 865.0666379214.

The spelling of 647364217 in words is "six hundred forty-seven million, three hundred sixty-four thousand, two hundred seventeen".