19891812103 has 2 divisors, whose sum is σ = 19891812104. Its totient is φ = 19891812102.

The previous prime is 19891812089. The next prime is 19891812137. The reversal of 19891812103 is 30121819891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19891812103 - 2²¹ = 19889714951 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19891812103.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19891812203) 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, 9945906051 + 9945906052.

It is an arithmetic number, because the mean of its divisors is an integer number (9945906052).

Almost surely, 2^19891812103 is an apocalyptic number.

19891812103 is a deficient number, since it is larger than the sum of its proper divisors (1).

19891812103 is an equidigital number, since it uses as much as digits as its factorization.

19891812103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 43.

The spelling of 19891812103 in words is "nineteen billion, eight hundred ninety-one million, eight hundred twelve thousand, one hundred three".