9118721 has 2 divisors, whose sum is σ = 9118722. Its totient is φ = 9118720.

The previous prime is 9118699. The next prime is 9118751. The reversal of 9118721 is 1278119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6558721 + 2560000 = 2561^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 9118721 - 2¹⁰ = 9117697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9118751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4559360 + 4559361.

It is an arithmetic number, because the mean of its divisors is an integer number (4559361).

Almost surely, 2^9118721 is an apocalyptic number.

It is an amenable number.

9118721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9118721 is an equidigital number, since it uses as much as digits as its factorization.

9118721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 29.

The square root of 9118721 is about 3019.7220070728. The cubic root of 9118721 is about 208.9190180980.

The spelling of 9118721 in words is "nine million, one hundred eighteen thousand, seven hundred twenty-one".