9981121 has 2 divisors, whose sum is σ = 9981122. Its totient is φ = 9981120.

The previous prime is 9981079. The next prime is 9981143. The reversal of 9981121 is 1211899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7535025 + 2446096 = 2745^2 + 1564^2 .

It is a cyclic number.

It is not a de Polignac number, because 9981121 - 2¹⁹ = 9456833 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (9981151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990560 + 4990561.

It is an arithmetic number, because the mean of its divisors is an integer number (4990561).

Almost surely, 2^9981121 is an apocalyptic number.

It is an amenable number.

9981121 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981121 is an equidigital number, since it uses as much as digits as its factorization.

9981121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 31.

The square root of 9981121 is about 3159.2912179791. The cubic root of 9981121 is about 215.3078050189.

The spelling of 9981121 in words is "nine million, nine hundred eighty-one thousand, one hundred twenty-one".