19688789 has 2 divisors, whose sum is σ = 19688790. Its totient is φ = 19688788.

The previous prime is 19688777. The next prime is 19688791. The reversal of 19688789 is 98788691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11336689 + 8352100 = 3367^2 + 2890^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19688789 is a prime.

Together with 19688791, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19688719) 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, 9844394 + 9844395.

It is an arithmetic number, because the mean of its divisors is an integer number (9844395).

Almost surely, 2^19688789 is an apocalyptic number.

It is an amenable number.

19688789 is a deficient number, since it is larger than the sum of its proper divisors (1).

19688789 is an equidigital number, since it uses as much as digits as its factorization.

19688789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 56.

The square root of 19688789 is about 4437.2050887918. The cubic root of 19688789 is about 270.0264674557.

The spelling of 19688789 in words is "nineteen million, six hundred eighty-eight thousand, seven hundred eighty-nine".