197121791 has 2 divisors, whose sum is σ = 197121792. Its totient is φ = 197121790.

The previous prime is 197121767. The next prime is 197121811.

197121791 is nontrivially palindromic in base 10.

It is a strong prime.

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 197121791 - 2¹⁴ = 197105407 is a 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 (197121731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98560895 + 98560896.

It is an arithmetic number, because the mean of its divisors is an integer number (98560896).

Almost surely, 2^197121791 is an apocalyptic number.

197121791 is a deficient number, since it is larger than the sum of its proper divisors (1).

197121791 is an equidigital number, since it uses as much as digits as its factorization.

197121791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7938, while the sum is 38.

The square root of 197121791 is about 14040.0068019927. The cubic root of 197121791 is about 581.9846704984.

The spelling of 197121791 in words is "one hundred ninety-seven million, one hundred twenty-one thousand, seven hundred ninety-one".