197597921657 has 2 divisors, whose sum is σ = 197597921658. Its totient is φ = 197597921656.

The previous prime is 197597921581. The next prime is 197597921659. The reversal of 197597921657 is 756129795791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162458169721 + 35139751936 = 403061^2 + 187456^2 .

It is a cyclic number.

It is not a de Polignac number, because 197597921657 - 2¹⁰ = 197597920633 is a prime.

Together with 197597921659, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (197597921659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98798960828 + 98798960829.

It is an arithmetic number, because the mean of its divisors is an integer number (98798960829).

Almost surely, 2^197597921657 is an apocalyptic number.

It is an amenable number.

197597921657 is a deficient number, since it is larger than the sum of its proper divisors (1).

197597921657 is an equidigital number, since it uses as much as digits as its factorization.

197597921657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75014100, while the sum is 68.

The spelling of 197597921657 in words is "one hundred ninety-seven billion, five hundred ninety-seven million, nine hundred twenty-one thousand, six hundred fifty-seven".