19794895649 has 2 divisors, whose sum is σ = 19794895650. Its totient is φ = 19794895648.

The previous prime is 19794895643. The next prime is 19794895663. The reversal of 19794895649 is 94659849791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17251509025 + 2543386624 = 131345^2 + 50432^2 .

It is a cyclic number.

It is not a de Polignac number, because 19794895649 - 2¹⁶ = 19794830113 is a prime.

It is a super-3 number, since 3×19794895649³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19794895643) 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, 9897447824 + 9897447825.

It is an arithmetic number, because the mean of its divisors is an integer number (9897447825).

Almost surely, 2^19794895649 is an apocalyptic number.

It is an amenable number.

19794895649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19794895649 is an equidigital number, since it uses as much as digits as its factorization.

19794895649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 176359680, while the sum is 71.

The spelling of 19794895649 in words is "nineteen billion, seven hundred ninety-four million, eight hundred ninety-five thousand, six hundred forty-nine".