9981161 has 2 divisors, whose sum is σ = 9981162. Its totient is φ = 9981160.

The previous prime is 9981151. The next prime is 9981197. The reversal of 9981161 is 1611899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8737936 + 1243225 = 2956^2 + 1115^2 .

It is an emirp because it is prime and its reverse (1611899) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9981161 is a prime.

It is not a weakly prime, because it can be changed into another prime (9981121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990580 + 4990581.

It is an arithmetic number, because the mean of its divisors is an integer number (4990581).

Almost surely, 2^9981161 is an apocalyptic number.

It is an amenable number.

9981161 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981161 is an equidigital number, since it uses as much as digits as its factorization.

9981161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 35.

The square root of 9981161 is about 3159.2975485066. The cubic root of 9981161 is about 215.3080926386.

The spelling of 9981161 in words is "nine million, nine hundred eighty-one thousand, one hundred sixty-one".