19986389 has 2 divisors, whose sum is σ = 19986390. Its totient is φ = 19986388.

The previous prime is 19986383. The next prime is 19986397. The reversal of 19986389 is 98368991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19731364 + 255025 = 4442^2 + 505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19986389 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 19986389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19986383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9993194 + 9993195.

It is an arithmetic number, because the mean of its divisors is an integer number (9993195).

Almost surely, 2^19986389 is an apocalyptic number.

It is an amenable number.

19986389 is a deficient number, since it is larger than the sum of its proper divisors (1).

19986389 is an equidigital number, since it uses as much as digits as its factorization.

19986389 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 19986389 is about 4470.6139399416. The cubic root of 19986389 is about 271.3801711219.

The spelling of 19986389 in words is "nineteen million, nine hundred eighty-six thousand, three hundred eighty-nine".