19968889 has 2 divisors, whose sum is σ = 19968890. Its totient is φ = 19968888.

The previous prime is 19968877. The next prime is 19968911. The reversal of 19968889 is 98886991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19316025 + 652864 = 4395^2 + 808^2 .

It is a cyclic number.

It is not a de Polignac number, because 19968889 - 2¹¹ = 19966841 is a prime.

It is not a weakly prime, because it can be changed into another prime (19968869) 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, 9984444 + 9984445.

It is an arithmetic number, because the mean of its divisors is an integer number (9984445).

Almost surely, 2^19968889 is an apocalyptic number.

It is an amenable number.

19968889 is a deficient number, since it is larger than the sum of its proper divisors (1).

19968889 is an equidigital number, since it uses as much as digits as its factorization.

19968889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 58.

The square root of 19968889 is about 4468.6562857306. The cubic root of 19968889 is about 271.3009415392.

The spelling of 19968889 in words is "nineteen million, nine hundred sixty-eight thousand, eight hundred eighty-nine".