19998565529 has 2 divisors, whose sum is σ = 19998565530. Its totient is φ = 19998565528.

The previous prime is 19998565513. The next prime is 19998565549. The reversal of 19998565529 is 92556589991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11092302400 + 8906263129 = 105320^2 + 94373^2 .

It is a cyclic number.

It is not a de Polignac number, because 19998565529 - 2⁴ = 19998565513 is a prime.

It is not a weakly prime, because it can be changed into another prime (19998565549) 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, 9999282764 + 9999282765.

It is an arithmetic number, because the mean of its divisors is an integer number (9999282765).

Almost surely, 2^19998565529 is an apocalyptic number.

It is an amenable number.

19998565529 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998565529 is an equidigital number, since it uses as much as digits as its factorization.

19998565529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732000, while the sum is 68.

The spelling of 19998565529 in words is "nineteen billion, nine hundred ninety-eight million, five hundred sixty-five thousand, five hundred twenty-nine".