197729981 has 2 divisors, whose sum is σ = 197729982. Its totient is φ = 197729980.

The previous prime is 197729977. The next prime is 197730031. The reversal of 197729981 is 189927791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 165353881 + 32376100 = 12859^2 + 5690^2 .

It is a cyclic number.

It is not a de Polignac number, because 197729981 - 2² = 197729977 is a prime.

It is a super-2 number, since 2×197729981² = 78194290772520722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197729951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98864990 + 98864991.

It is an arithmetic number, because the mean of its divisors is an integer number (98864991).

Almost surely, 2^197729981 is an apocalyptic number.

It is an amenable number.

197729981 is a deficient number, since it is larger than the sum of its proper divisors (1).

197729981 is an equidigital number, since it uses as much as digits as its factorization.

197729981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 53.

The square root of 197729981 is about 14061.6492987131. The cubic root of 197729981 is about 582.5825983922.

The spelling of 197729981 in words is "one hundred ninety-seven million, seven hundred twenty-nine thousand, nine hundred eighty-one".