19999989 has 12 divisors (see below), whose sum is σ = 30409600. Its totient is φ = 12631464.

The previous prime is 19999981. The next prime is 19999999. The reversal of 19999989 is 98999991.

It is not a de Polignac number, because 19999989 - 2³ = 19999981 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19999981) 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 in 11 ways as a sum of consecutive naturals, for example, 58309 + ... + 58650.

Almost surely, 2^19999989 is an apocalyptic number.

19999989 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19999989 is a deficient number, since it is larger than the sum of its proper divisors (10409611).

19999989 is a wasteful number, since it uses less digits than its factorization.

19999989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116984 (or 116981 counting only the distinct ones).

The product of its digits is 4251528, while the sum is 63.

The square root of 19999989 is about 4472.1347251620. The cubic root of 19999989 is about 271.4417118952.

The spelling of 19999989 in words is "nineteen million, nine hundred ninety-nine thousand, nine hundred eighty-nine".