9797557981 has 2 divisors, whose sum is σ = 9797557982. Its totient is φ = 9797557980.

The previous prime is 9797557951. The next prime is 9797557999. The reversal of 9797557981 is 1897557979.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7759848100 + 2037709881 = 88090^2 + 45141^2 .

It is a cyclic number.

It is not a de Polignac number, because 9797557981 - 2²⁵ = 9764003549 is a prime.

It is a super-2 number, since 2×9797557981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9797557901) 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, 4898778990 + 4898778991.

It is an arithmetic number, because the mean of its divisors is an integer number (4898778991).

Almost surely, 2^9797557981 is an apocalyptic number.

It is an amenable number.

9797557981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9797557981 is an equidigital number, since it uses as much as digits as its factorization.

9797557981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50009400, while the sum is 67.

The square root of 9797557981 is about 98982.6145391199. The cubic root of 9797557981 is about 2139.7971960402.

The spelling of 9797557981 in words is "nine billion, seven hundred ninety-seven million, five hundred fifty-seven thousand, nine hundred eighty-one".