9721189 has 2 divisors, whose sum is σ = 9721190. Its totient is φ = 9721188.

The previous prime is 9721183. The next prime is 9721199. The reversal of 9721189 is 9811279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6630625 + 3090564 = 2575^2 + 1758^2 .

It is a cyclic number.

It is not a de Polignac number, because 9721189 - 2³ = 9721181 is a prime.

9721189 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9721181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4860594 + 4860595.

It is an arithmetic number, because the mean of its divisors is an integer number (4860595).

Almost surely, 2^9721189 is an apocalyptic number.

It is an amenable number.

9721189 is a deficient number, since it is larger than the sum of its proper divisors (1).

9721189 is an equidigital number, since it uses as much as digits as its factorization.

9721189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 37.

The square root of 9721189 is about 3117.8821337568. The cubic root of 9721189 is about 213.4222998614.

The spelling of 9721189 in words is "nine million, seven hundred twenty-one thousand, one hundred eighty-nine".