647666297 has 2 divisors, whose sum is σ = 647666298. Its totient is φ = 647666296.

The previous prime is 647666263. The next prime is 647666311. The reversal of 647666297 is 792666746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 646634041 + 1032256 = 25429^2 + 1016^2 .

It is a cyclic number.

It is not a de Polignac number, because 647666297 - 2⁶ = 647666233 is a prime.

It is not a weakly prime, because it can be changed into another prime (647666207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323833148 + 323833149.

It is an arithmetic number, because the mean of its divisors is an integer number (323833149).

Almost surely, 2^647666297 is an apocalyptic number.

It is an amenable number.

647666297 is a deficient number, since it is larger than the sum of its proper divisors (1).

647666297 is an equidigital number, since it uses as much as digits as its factorization.

647666297 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 53.

The square root of 647666297 is about 25449.2887326935. The cubic root of 647666297 is about 865.2011725400.

The spelling of 647666297 in words is "six hundred forty-seven million, six hundred sixty-six thousand, two hundred ninety-seven".