19980836591 has 2 divisors, whose sum is σ = 19980836592. Its totient is φ = 19980836590.

The previous prime is 19980836581. The next prime is 19980836597. The reversal of 19980836591 is 19563808991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19980836591 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19980836591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19980836597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9990418295 + 9990418296.

It is an arithmetic number, because the mean of its divisors is an integer number (9990418296).

Almost surely, 2^19980836591 is an apocalyptic number.

19980836591 is a deficient number, since it is larger than the sum of its proper divisors (1).

19980836591 is an equidigital number, since it uses as much as digits as its factorization.

19980836591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4199040, while the sum is 59.

The spelling of 19980836591 in words is "nineteen billion, nine hundred eighty million, eight hundred thirty-six thousand, five hundred ninety-one".