19688399 has 2 divisors, whose sum is σ = 19688400. Its totient is φ = 19688398.

The previous prime is 19688393. The next prime is 19688411. The reversal of 19688399 is 99388691.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19688399 - 2¹² = 19684303 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19688399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19688393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9844199 + 9844200.

It is an arithmetic number, because the mean of its divisors is an integer number (9844200).

Almost surely, 2^19688399 is an apocalyptic number.

19688399 is a deficient number, since it is larger than the sum of its proper divisors (1).

19688399 is an equidigital number, since it uses as much as digits as its factorization.

19688399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 53.

The square root of 19688399 is about 4437.1611419916. The cubic root of 19688399 is about 270.0246845287.

The spelling of 19688399 in words is "nineteen million, six hundred eighty-eight thousand, three hundred ninety-nine".