19638943 has 2 divisors, whose sum is σ = 19638944. Its totient is φ = 19638942.

The previous prime is 19638937. The next prime is 19638967. The reversal of 19638943 is 34983691.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19638943 - 2⁹ = 19638431 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19638943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19638923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9819471 + 9819472.

It is an arithmetic number, because the mean of its divisors is an integer number (9819472).

Almost surely, 2^19638943 is an apocalyptic number.

19638943 is a deficient number, since it is larger than the sum of its proper divisors (1).

19638943 is an equidigital number, since it uses as much as digits as its factorization.

19638943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 43.

The square root of 19638943 is about 4431.5847052719. The cubic root of 19638943 is about 269.7984000354.

The spelling of 19638943 in words is "nineteen million, six hundred thirty-eight thousand, nine hundred forty-three".