647662217 has 2 divisors, whose sum is σ = 647662218. Its totient is φ = 647662216.

The previous prime is 647662201. The next prime is 647662237. The reversal of 647662217 is 712266746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 466732816 + 180929401 = 21604^2 + 13451^2 .

It is a cyclic number.

It is not a de Polignac number, because 647662217 - 2⁴ = 647662201 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647662237) 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, 323831108 + 323831109.

It is an arithmetic number, because the mean of its divisors is an integer number (323831109).

Almost surely, 2^647662217 is an apocalyptic number.

It is an amenable number.

647662217 is a deficient number, since it is larger than the sum of its proper divisors (1).

647662217 is an equidigital number, since it uses as much as digits as its factorization.

647662217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 41.

The square root of 647662217 is about 25449.2085731561. The cubic root of 647662217 is about 865.1993557463.

The spelling of 647662217 in words is "six hundred forty-seven million, six hundred sixty-two thousand, two hundred seventeen".