18729899849 has 2 divisors, whose sum is σ = 18729899850. Its totient is φ = 18729899848.

The previous prime is 18729899813. The next prime is 18729899911. The reversal of 18729899849 is 94899892781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17013289225 + 1716610624 = 130435^2 + 41432^2 .

It is a cyclic number.

It is not a de Polignac number, because 18729899849 - 2¹⁶ = 18729834313 is a prime.

It is not a weakly prime, because it can be changed into another prime (18729599849) 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, 9364949924 + 9364949925.

It is an arithmetic number, because the mean of its divisors is an integer number (9364949925).

Almost surely, 2^18729899849 is an apocalyptic number.

It is an amenable number.

18729899849 is a deficient number, since it is larger than the sum of its proper divisors (1).

18729899849 is an equidigital number, since it uses as much as digits as its factorization.

18729899849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188116992, while the sum is 74.

The spelling of 18729899849 in words is "eighteen billion, seven hundred twenty-nine million, eight hundred ninety-nine thousand, eight hundred forty-nine".