9889921 has 2 divisors, whose sum is σ = 9889922. Its totient is φ = 9889920.

The previous prime is 9889909. The next prime is 9889927. The reversal of 9889921 is 1299889.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9678321 + 211600 = 3111^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 9889921 - 2⁵ = 9889889 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9889927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4944960 + 4944961.

It is an arithmetic number, because the mean of its divisors is an integer number (4944961).

Almost surely, 2^9889921 is an apocalyptic number.

It is an amenable number.

9889921 is a deficient number, since it is larger than the sum of its proper divisors (1).

9889921 is an equidigital number, since it uses as much as digits as its factorization.

9889921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 46.

The square root of 9889921 is about 3144.8244784089. The cubic root of 9889921 is about 214.6500237323.

The spelling of 9889921 in words is "nine million, eight hundred eighty-nine thousand, nine hundred twenty-one".