9931121 has 2 divisors, whose sum is σ = 9931122. Its totient is φ = 9931120.

The previous prime is 9931109. The next prime is 9931123. The reversal of 9931121 is 1211399.

9931121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8620096 + 1311025 = 2936^2 + 1145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9931121 is a prime.

It is a Sophie Germain prime.

Together with 9931123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (9931123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4965560 + 4965561.

It is an arithmetic number, because the mean of its divisors is an integer number (4965561).

Almost surely, 2^9931121 is an apocalyptic number.

It is an amenable number.

9931121 is a deficient number, since it is larger than the sum of its proper divisors (1).

9931121 is an equidigital number, since it uses as much as digits as its factorization.

9931121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 486, while the sum is 26.

The square root of 9931121 is about 3151.3681155968. The cubic root of 9931121 is about 214.9476779116.

The spelling of 9931121 in words is "nine million, nine hundred thirty-one thousand, one hundred twenty-one".