634638197 has 2 divisors, whose sum is σ = 634638198. Its totient is φ = 634638196.

The previous prime is 634638187. The next prime is 634638223. The reversal of 634638197 is 791836436.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 634334596 + 303601 = 25186^2 + 551^2 .

It is a cyclic number.

It is not a de Polignac number, because 634638197 - 2²⁸ = 366202741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634638127) 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, 317319098 + 317319099.

It is an arithmetic number, because the mean of its divisors is an integer number (317319099).

Almost surely, 2^634638197 is an apocalyptic number.

It is an amenable number.

634638197 is a deficient number, since it is larger than the sum of its proper divisors (1).

634638197 is an equidigital number, since it uses as much as digits as its factorization.

634638197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 47.

The square root of 634638197 is about 25192.0264567978. The cubic root of 634638197 is about 859.3605292232.

The spelling of 634638197 in words is "six hundred thirty-four million, six hundred thirty-eight thousand, one hundred ninety-seven".