19819803636 has 18 divisors (see below), whose sum is σ = 50100059282. Its totient is φ = 6606601200.

The previous prime is 19819803623. The next prime is 19819803671. The reversal of 19819803636 is 63630891891.

19819803636 is a `hidden beast` number, since 1 + 98 + 198 + 0 + 363 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17822250000 + 1997553636 = 133500^2 + 44694^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 275275015 + ... + 275275086.

Almost surely, 2^19819803636 is an apocalyptic number.

It is an amenable number.

19819803636 is an abundant number, since it is smaller than the sum of its proper divisors (30280255646).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19819803636 is a wasteful number, since it uses less digits than its factorization.

19819803636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550550111 (or 550550106 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 19819803636 in words is "nineteen billion, eight hundred nineteen million, eight hundred three thousand, six hundred thirty-six".