19686838009 has 2 divisors, whose sum is σ = 19686838010. Its totient is φ = 19686838008.

The previous prime is 19686837967. The next prime is 19686838013. The reversal of 19686838009 is 90083868691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19174494784 + 512343225 = 138472^2 + 22635^2 .

It is a cyclic number.

It is not a de Polignac number, because 19686838009 - 2⁷ = 19686837881 is a prime.

It is not a weakly prime, because it can be changed into another prime (19686839009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9843419004 + 9843419005.

It is an arithmetic number, because the mean of its divisors is an integer number (9843419005).

Almost surely, 2^19686838009 is an apocalyptic number.

It is an amenable number.

19686838009 is a deficient number, since it is larger than the sum of its proper divisors (1).

19686838009 is an equidigital number, since it uses as much as digits as its factorization.

19686838009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4478976, while the sum is 58.

The spelling of 19686838009 in words is "nineteen billion, six hundred eighty-six million, eight hundred thirty-eight thousand, nine".