19811125493 has 2 divisors, whose sum is σ = 19811125494. Its totient is φ = 19811125492.

The previous prime is 19811125483. The next prime is 19811125517. The reversal of 19811125493 is 39452111891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19512457969 + 298667524 = 139687^2 + 17282^2 .

It is a cyclic number.

It is not a de Polignac number, because 19811125493 - 2²² = 19806931189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19811125483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9905562746 + 9905562747.

It is an arithmetic number, because the mean of its divisors is an integer number (9905562747).

Almost surely, 2^19811125493 is an apocalyptic number.

It is an amenable number.

19811125493 is a deficient number, since it is larger than the sum of its proper divisors (1).

19811125493 is an equidigital number, since it uses as much as digits as its factorization.

19811125493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 44.

The spelling of 19811125493 in words is "nineteen billion, eight hundred eleven million, one hundred twenty-five thousand, four hundred ninety-three".