9168721 has 2 divisors, whose sum is σ = 9168722. Its totient is φ = 9168720.

The previous prime is 9168701. The next prime is 9168737. The reversal of 9168721 is 1278619.

It is a happy number.

9168721 is digitally balanced in base 3, 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., 8850625 + 318096 = 2975^2 + 564^2 .

It is an emirp because it is prime and its reverse (1278619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9168721 - 2⁵ = 9168689 is a prime.

It is not a weakly prime, because it can be changed into another prime (9168701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4584360 + 4584361.

It is an arithmetic number, because the mean of its divisors is an integer number (4584361).

Almost surely, 2^9168721 is an apocalyptic number.

It is an amenable number.

9168721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9168721 is an equidigital number, since it uses as much as digits as its factorization.

9168721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 9168721 is about 3027.9895970759. The cubic root of 9168721 is about 209.3001722955.

It can be divided in two parts, 9168 and 721, that added together give a palindrome (9889).

The spelling of 9168721 in words is "nine million, one hundred sixty-eight thousand, seven hundred twenty-one".