19888889 has 2 divisors, whose sum is σ = 19888890. Its totient is φ = 19888888.

The previous prime is 19888873. The next prime is 19888901. The reversal of 19888889 is 98888891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13935289 + 5953600 = 3733^2 + 2440^2 .

It is a cyclic number.

It is not a de Polignac number, because 19888889 - 2⁴ = 19888873 is a prime.

It is not a weakly prime, because it can be changed into another prime (19888189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9944444 + 9944445.

It is an arithmetic number, because the mean of its divisors is an integer number (9944445).

Almost surely, 2^19888889 is an apocalyptic number.

It is an amenable number.

19888889 is a deficient number, since it is larger than the sum of its proper divisors (1).

19888889 is an equidigital number, since it uses as much as digits as its factorization.

19888889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2654208, while the sum is 59.

The square root of 19888889 is about 4459.6960658771. The cubic root of 19888889 is about 270.9381584811.

The spelling of 19888889 in words is "nineteen million, eight hundred eighty-eight thousand, eight hundred eighty-nine".