19864636738 has 16 divisors (see below), whose sum is σ = 30672037440. Its totient is φ = 9641848176.

The previous prime is 19864636681. The next prime is 19864636739. The reversal of 19864636738 is 83763646891.

It is not an unprimeable number, because it can be changed into a prime (19864636739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273256 + ... + 338227.

It is an arithmetic number, because the mean of its divisors is an integer number (1917002340).

Almost surely, 2^19864636738 is an apocalyptic number.

19864636738 is a deficient number, since it is larger than the sum of its proper divisors (10807400702).

19864636738 is a wasteful number, since it uses less digits than its factorization.

19864636738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611961.

The product of its digits is 31352832, while the sum is 61.

The spelling of 19864636738 in words is "nineteen billion, eight hundred sixty-four million, six hundred thirty-six thousand, seven hundred thirty-eight".