19827971543 has 2 divisors, whose sum is σ = 19827971544. Its totient is φ = 19827971542.

The previous prime is 19827971521. The next prime is 19827971549. The reversal of 19827971543 is 34517972891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19827971543 - 2¹² = 19827967447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19827971549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9913985771 + 9913985772.

It is an arithmetic number, because the mean of its divisors is an integer number (9913985772).

Almost surely, 2^19827971543 is an apocalyptic number.

19827971543 is a deficient number, since it is larger than the sum of its proper divisors (1).

19827971543 is an equidigital number, since it uses as much as digits as its factorization.

19827971543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3810240, while the sum is 56.

The spelling of 19827971543 in words is "nineteen billion, eight hundred twenty-seven million, nine hundred seventy-one thousand, five hundred forty-three".