19867819117 has 2 divisors, whose sum is σ = 19867819118. Its totient is φ = 19867819116.

The previous prime is 19867819087. The next prime is 19867819187. The reversal of 19867819117 is 71191876891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17537440041 + 2330379076 = 132429^2 + 48274^2 .

It is a cyclic number.

It is not a de Polignac number, because 19867819117 - 2⁷ = 19867818989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19867819187) 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, 9933909558 + 9933909559.

It is an arithmetic number, because the mean of its divisors is an integer number (9933909559).

Almost surely, 2^19867819117 is an apocalyptic number.

It is an amenable number.

19867819117 is a deficient number, since it is larger than the sum of its proper divisors (1).

19867819117 is an equidigital number, since it uses as much as digits as its factorization.

19867819117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 58.

The spelling of 19867819117 in words is "nineteen billion, eight hundred sixty-seven million, eight hundred nineteen thousand, one hundred seventeen".