197709121 has 4 divisors (see below), whose sum is σ = 198557892. Its totient is φ = 196860352.

The previous prime is 197709097. The next prime is 197709137. The reversal of 197709121 is 121907791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88736400 + 108972721 = 9420^2 + 10439^2 .

It is a cyclic number.

It is not a de Polignac number, because 197709121 - 2⁷ = 197708993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197709151) 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 in 3 ways as a sum of consecutive naturals, for example, 424036 + ... + 424501.

It is an arithmetic number, because the mean of its divisors is an integer number (49639473).

Almost surely, 2^197709121 is an apocalyptic number.

It is an amenable number.

197709121 is a deficient number, since it is larger than the sum of its proper divisors (848771).

197709121 is an equidigital number, since it uses as much as digits as its factorization.

197709121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 848770.

The product of its (nonzero) digits is 7938, while the sum is 37.

The square root of 197709121 is about 14060.9075453898. The cubic root of 197709121 is about 582.5621106875.

The spelling of 197709121 in words is "one hundred ninety-seven million, seven hundred nine thousand, one hundred twenty-one".