19898791439 has 2 divisors, whose sum is σ = 19898791440. Its totient is φ = 19898791438.

The previous prime is 19898791421. The next prime is 19898791459. The reversal of 19898791439 is 93419789891.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19898791439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19898791459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949395719 + 9949395720.

It is an arithmetic number, because the mean of its divisors is an integer number (9949395720).

Almost surely, 2^19898791439 is an apocalyptic number.

19898791439 is a deficient number, since it is larger than the sum of its proper divisors (1).

19898791439 is an equidigital number, since it uses as much as digits as its factorization.

19898791439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35271936, while the sum is 68.

The spelling of 19898791439 in words is "nineteen billion, eight hundred ninety-eight million, seven hundred ninety-one thousand, four hundred thirty-nine".