19990597943 has 2 divisors, whose sum is σ = 19990597944. Its totient is φ = 19990597942.

The previous prime is 19990597903. The next prime is 19990597987. The reversal of 19990597943 is 34979509991.

It is a weak prime.

It is an emirp because it is prime and its reverse (34979509991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19990597943 - 2¹⁰ = 19990596919 is a prime.

It is a super-2 number, since 2×19990597943² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19990597943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19990597903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9995298971 + 9995298972.

It is an arithmetic number, because the mean of its divisors is an integer number (9995298972).

Almost surely, 2^19990597943 is an apocalyptic number.

19990597943 is a deficient number, since it is larger than the sum of its proper divisors (1).

19990597943 is an equidigital number, since it uses as much as digits as its factorization.

19990597943 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24800580, while the sum is 65.

It can be divided in two parts, 1999059 and 7943, that added together give a palindrome (2007002).

The spelling of 19990597943 in words is "nineteen billion, nine hundred ninety million, five hundred ninety-seven thousand, nine hundred forty-three".