19989727 has 2 divisors, whose sum is σ = 19989728. Its totient is φ = 19989726.

The previous prime is 19989719. The next prime is 19989743. The reversal of 19989727 is 72798991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19989727 - 2³ = 19989719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19989707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9994863 + 9994864.

It is an arithmetic number, because the mean of its divisors is an integer number (9994864).

Almost surely, 2^19989727 is an apocalyptic number.

19989727 is a deficient number, since it is larger than the sum of its proper divisors (1).

19989727 is an equidigital number, since it uses as much as digits as its factorization.

19989727 is an evil number, because the sum of its binary digits is even.

The product of its digits is 571536, while the sum is 52.

The square root of 19989727 is about 4470.9872511561. The cubic root of 19989727 is about 271.3952783462.

The spelling of 19989727 in words is "nineteen million, nine hundred eighty-nine thousand, seven hundred twenty-seven".