19818563798 has 32 divisors (see below), whose sum is σ = 33077797632. Its totient is φ = 8828965600.

The previous prime is 19818563789. The next prime is 19818563813. The reversal of 19818563798 is 89736581891.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 1137533 + ... + 1154823.

It is an arithmetic number, because the mean of its divisors is an integer number (1033681176).

Almost surely, 2^19818563798 is an apocalyptic number.

19818563798 is a deficient number, since it is larger than the sum of its proper divisors (13259233834).

19818563798 is a wasteful number, since it uses less digits than its factorization.

19818563798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18340.

The product of its digits is 26127360, while the sum is 65.

The spelling of 19818563798 in words is "nineteen billion, eight hundred eighteen million, five hundred sixty-three thousand, seven hundred ninety-eight".