19986566738 has 8 divisors (see below), whose sum is σ = 29984965500. Its totient is φ = 9991578240.

The previous prime is 19986566687. The next prime is 19986566777. The reversal of 19986566738 is 83766568991.

It can be written as a sum of positive squares in 2 ways, for example, as 19296821569 + 689745169 = 138913^2 + 26263^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 837863 + ... + 861386.

Almost surely, 2^19986566738 is an apocalyptic number.

19986566738 is a deficient number, since it is larger than the sum of its proper divisors (9998398762).

19986566738 is a wasteful number, since it uses less digits than its factorization.

19986566738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705132.

The product of its digits is 117573120, while the sum is 68.

The spelling of 19986566738 in words is "nineteen billion, nine hundred eighty-six million, five hundred sixty-six thousand, seven hundred thirty-eight".