19899689 has 2 divisors, whose sum is σ = 19899690. Its totient is φ = 19899688.

The previous prime is 19899679. The next prime is 19899721. The reversal of 19899689 is 98699891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19430464 + 469225 = 4408^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899689 - 2²⁴ = 3122473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19899629) 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, 9949844 + 9949845.

It is an arithmetic number, because the mean of its divisors is an integer number (9949845).

Almost surely, 2^19899689 is an apocalyptic number.

It is an amenable number.

19899689 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899689 is an equidigital number, since it uses as much as digits as its factorization.

19899689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 59.

The square root of 19899689 is about 4460.9067463914. The cubic root of 19899689 is about 270.9871909270.

The spelling of 19899689 in words is "nineteen million, eight hundred ninety-nine thousand, six hundred eighty-nine".