197556562943981 has 2 divisors, whose sum is σ = 197556562943982. Its totient is φ = 197556562943980.

The previous prime is 197556562943977. The next prime is 197556562944011. The reversal of 197556562943981 is 189349265655791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139368271928356 + 58188291015625 = 11805434^2 + 7628125^2 .

It is a cyclic number.

It is not a de Polignac number, because 197556562943981 - 2² = 197556562943977 is a prime.

It is a super-2 number, since 2×197556562943981² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 197556562943896 and 197556562943905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197556562943921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98778281471990 + 98778281471991.

It is an arithmetic number, because the mean of its divisors is an integer number (98778281471991).

Almost surely, 2^{197556562943981} is an apocalyptic number.

It is an amenable number.

197556562943981 is a deficient number, since it is larger than the sum of its proper divisors (1).

197556562943981 is an equidigital number, since it uses as much as digits as its factorization.

197556562943981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4408992000, while the sum is 80.

The spelling of 197556562943981 in words is "one hundred ninety-seven trillion, five hundred fifty-six billion, five hundred sixty-two million, nine hundred forty-three thousand, nine hundred eighty-one".