1999642185684 has 528 divisors, whose sum is σ = 6258877122624. Its totient is φ = 550998028800.

The previous prime is 1999642185661. The next prime is 1999642185721. The reversal of 1999642185684 is 4865812469991.

1999642185684 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 6 + 42 + 18 + 568 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 175 ways as a sum of consecutive naturals, for example, 2465649639 + ... + 2465650449.

Almost surely, 2^{1999642185684} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999642185684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3129438561312).

1999642185684 is an abundant number, since it is smaller than the sum of its proper divisors (4259234936940).

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

1999642185684 is a wasteful number, since it uses less digits than its factorization.

1999642185684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942 (or 913 counting only the distinct ones).

The product of its digits is 268738560, while the sum is 72.

The spelling of 1999642185684 in words is "one trillion, nine hundred ninety-nine billion, six hundred forty-two million, one hundred eighty-five thousand, six hundred eighty-four".