19715859649 has 2 divisors, whose sum is σ = 19715859650. Its totient is φ = 19715859648.

The previous prime is 19715859629. The next prime is 19715859659. The reversal of 19715859649 is 94695851791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18071962624 + 1643897025 = 134432^2 + 40545^2 .

It is a cyclic number.

It is not a de Polignac number, because 19715859649 - 2⁷ = 19715859521 is a prime.

It is not a weakly prime, because it can be changed into another prime (19715859619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9857929824 + 9857929825.

It is an arithmetic number, because the mean of its divisors is an integer number (9857929825).

Almost surely, 2^19715859649 is an apocalyptic number.

It is an amenable number.

19715859649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19715859649 is an equidigital number, since it uses as much as digits as its factorization.

19715859649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24494400, while the sum is 64.

The spelling of 19715859649 in words is "nineteen billion, seven hundred fifteen million, eight hundred fifty-nine thousand, six hundred forty-nine".