9921889 has 2 divisors, whose sum is σ = 9921890. Its totient is φ = 9921888.

The previous prime is 9921869. The next prime is 9921907. The reversal of 9921889 is 9881299.

It is a happy number.

9921889 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., 9734400 + 187489 = 3120^2 + 433^2 .

It is an emirp because it is prime and its reverse (9881299) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9921889 - 2¹¹ = 9919841 is a prime.

It is not a weakly prime, because it can be changed into another prime (9921869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4960944 + 4960945.

It is an arithmetic number, because the mean of its divisors is an integer number (4960945).

Almost surely, 2^9921889 is an apocalyptic number.

It is an amenable number.

9921889 is a deficient number, since it is larger than the sum of its proper divisors (1).

9921889 is an equidigital number, since it uses as much as digits as its factorization.

9921889 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 9921889 is about 3149.9030143800. The cubic root of 9921889 is about 214.8810519258.

The spelling of 9921889 in words is "nine million, nine hundred twenty-one thousand, eight hundred eighty-nine".