19838515649 has 2 divisors, whose sum is σ = 19838515650. Its totient is φ = 19838515648.

The previous prime is 19838515643. The next prime is 19838515691. The reversal of 19838515649 is 94651583891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14655523600 + 5182992049 = 121060^2 + 71993^2 .

It is an emirp because it is prime and its reverse (94651583891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19838515649 - 2⁸ = 19838515393 is a prime.

It is a super-3 number, since 3×19838515649³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (19838515643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9919257824 + 9919257825.

It is an arithmetic number, because the mean of its divisors is an integer number (9919257825).

Almost surely, 2^19838515649 is an apocalyptic number.

It is an amenable number.

19838515649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19838515649 is an equidigital number, since it uses as much as digits as its factorization.

19838515649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9331200, while the sum is 59.

The spelling of 19838515649 in words is "nineteen billion, eight hundred thirty-eight million, five hundred fifteen thousand, six hundred forty-nine".