199821969443 has 2 divisors, whose sum is σ = 199821969444. Its totient is φ = 199821969442.

The previous prime is 199821969409. The next prime is 199821969481. The reversal of 199821969443 is 344969128991.

It is a weak prime.

It is an emirp because it is prime and its reverse (344969128991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199821969443 - 2⁸ = 199821969187 is a prime.

It is a super-3 number, since 3×199821969443³ (a number of 35 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 199821969443.

It is not a weakly prime, because it can be changed into another prime (199821962443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99910984721 + 99910984722.

It is an arithmetic number, because the mean of its divisors is an integer number (99910984722).

Almost surely, 2^199821969443 is an apocalyptic number.

199821969443 is a deficient number, since it is larger than the sum of its proper divisors (1).

199821969443 is an equidigital number, since it uses as much as digits as its factorization.

199821969443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30233088, while the sum is 65.

The spelling of 199821969443 in words is "one hundred ninety-nine billion, eight hundred twenty-one million, nine hundred sixty-nine thousand, four hundred forty-three".