19804157543 has 2 divisors, whose sum is σ = 19804157544. Its totient is φ = 19804157542.

The previous prime is 19804157509. The next prime is 19804157557. The reversal of 19804157543 is 34575140891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19804157543 - 2⁶ = 19804157479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19804157563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9902078771 + 9902078772.

It is an arithmetic number, because the mean of its divisors is an integer number (9902078772).

Almost surely, 2^19804157543 is an apocalyptic number.

19804157543 is a deficient number, since it is larger than the sum of its proper divisors (1).

19804157543 is an equidigital number, since it uses as much as digits as its factorization.

19804157543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 47.

The spelling of 19804157543 in words is "nineteen billion, eight hundred four million, one hundred fifty-seven thousand, five hundred forty-three".