19191019189 has 2 divisors, whose sum is σ = 19191019190. Its totient is φ = 19191019188.

The previous prime is 19191019163. The next prime is 19191019201. The reversal of 19191019189 is 98191019191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13379548900 + 5811470289 = 115670^2 + 76233^2 .

It is a cyclic number.

It is not a de Polignac number, because 19191019189 - 2⁵ = 19191019157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19191019889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9595509594 + 9595509595.

It is an arithmetic number, because the mean of its divisors is an integer number (9595509595).

Almost surely, 2^19191019189 is an apocalyptic number.

It is an amenable number.

19191019189 is a deficient number, since it is larger than the sum of its proper divisors (1).

19191019189 is an equidigital number, since it uses as much as digits as its factorization.

19191019189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 49.

The spelling of 19191019189 in words is "nineteen billion, one hundred ninety-one million, nineteen thousand, one hundred eighty-nine".