1999859869800 has 288 divisors, whose sum is σ = 7241621532600. Its totient is φ = 491674613760.

The previous prime is 1999859869729. The next prime is 1999859869801. The reversal of 1999859869800 is 89689589991.

1999859869800 is a `hidden beast` number, since 19 + 9 + 9 + 8 + 598 + 6 + 9 + 8 + 0 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 18539000964 + 1981320868836 = 136158^2 + 1407594^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1999859869800.

It is not an unprimeable number, because it can be changed into a prime (1999859869801) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19347054 + ... + 19450146.

Almost surely, 2^{1999859869800} is an apocalyptic number.

1999859869800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999859869800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3620810766300).

1999859869800 is an abundant number, since it is smaller than the sum of its proper divisors (5241761662800).

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

1999859869800 is a wasteful number, since it uses less digits than its factorization.

1999859869800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103957 (or 103945 counting only the distinct ones).

The product of its (nonzero) digits is 906992640, while the sum is 81.

The spelling of 1999859869800 in words is "one trillion, nine hundred ninety-nine billion, eight hundred fifty-nine million, eight hundred sixty-nine thousand, eight hundred".