19899889 has 2 divisors, whose sum is σ = 19899890. Its totient is φ = 19899888.

The previous prime is 19899881. The next prime is 19899947. The reversal of 19899889 is 98899891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16136289 + 3763600 = 4017^2 + 1940^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899889 - 2³ = 19899881 is a prime.

It is not a weakly prime, because it can be changed into another prime (19899881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949944 + 9949945.

It is an arithmetic number, because the mean of its divisors is an integer number (9949945).

Almost surely, 2^19899889 is an apocalyptic number.

It is an amenable number.

19899889 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899889 is an equidigital number, since it uses as much as digits as its factorization.

19899889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 61.

The square root of 19899889 is about 4460.9291633022. The cubic root of 19899889 is about 270.9880987679.

The spelling of 19899889 in words is "nineteen million, eight hundred ninety-nine thousand, eight hundred eighty-nine".