647171197 has 2 divisors, whose sum is σ = 647171198. Its totient is φ = 647171196.

The previous prime is 647171191. The next prime is 647171209. The reversal of 647171197 is 791171746.

647171197 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 418979961 + 228191236 = 20469^2 + 15106^2 .

It is a cyclic number.

It is not a de Polignac number, because 647171197 - 2⁷ = 647171069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647171191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323585598 + 323585599.

It is an arithmetic number, because the mean of its divisors is an integer number (323585599).

Almost surely, 2^647171197 is an apocalyptic number.

It is an amenable number.

647171197 is a deficient number, since it is larger than the sum of its proper divisors (1).

647171197 is an equidigital number, since it uses as much as digits as its factorization.

647171197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 74088, while the sum is 43.

The square root of 647171197 is about 25439.5596856549. The cubic root of 647171197 is about 864.9806524457.

The spelling of 647171197 in words is "six hundred forty-seven million, one hundred seventy-one thousand, one hundred ninety-seven".