18189939634 has 16 divisors (see below), whose sum is σ = 27565764408. Its totient is φ = 9001746432.

The previous prime is 18189939611. The next prime is 18189939637. The reversal of 18189939634 is 43693998181.

It can be written as a sum of positive squares in 4 ways, for example, as 15093351025 + 3096588609 = 122855^2 + 55647^2 .

It is not an unprimeable number, because it can be changed into a prime (18189939637) 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 in 7 ways as a sum of consecutive naturals, for example, 6159 + ... + 190834.

Almost surely, 2^18189939634 is an apocalyptic number.

18189939634 is a deficient number, since it is larger than the sum of its proper divisors (9375824774).

18189939634 is a wasteful number, since it uses less digits than its factorization.

18189939634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197469.

The product of its digits is 10077696, while the sum is 61.

The spelling of 18189939634 in words is "eighteen billion, one hundred eighty-nine million, nine hundred thirty-nine thousand, six hundred thirty-four".