197919791 has 2 divisors, whose sum is σ = 197919792. Its totient is φ = 197919790.

The previous prime is 197919781. The next prime is 197919803.

197919791 is nontrivially palindromic in base 10.

It is a weak prime.

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-197919791 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197919781) 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, 98959895 + 98959896.

It is an arithmetic number, because the mean of its divisors is an integer number (98959896).

Almost surely, 2^197919791 is an apocalyptic number.

197919791 is a deficient number, since it is larger than the sum of its proper divisors (1).

197919791 is an equidigital number, since it uses as much as digits as its factorization.

197919791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 321489, while the sum is 53.

The square root of 197919791 is about 14068.3968880608. The cubic root of 197919791 is about 582.7689546168.

The spelling of 197919791 in words is "one hundred ninety-seven million, nine hundred nineteen thousand, seven hundred ninety-one".