1999800187 has 32 divisors (see below), whose sum is σ = 2554467840. Its totient is φ = 1520363520.

The previous prime is 1999800181. The next prime is 1999800191. The reversal of 1999800187 is 7810089991.

It is a cyclic number.

It is not a de Polignac number, because 1999800187 - 2¹⁹ = 1999275899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999800181) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 786364 + ... + 788902.

It is an arithmetic number, because the mean of its divisors is an integer number (79827120).

Almost surely, 2^1999800187 is an apocalyptic number.

1999800187 is a deficient number, since it is larger than the sum of its proper divisors (554667653).

1999800187 is a wasteful number, since it uses less digits than its factorization.

1999800187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2803.

The product of its (nonzero) digits is 326592, while the sum is 52.

The square root of 1999800187 is about 44719.1255169419. The cubic root of 1999800187 is about 1259.8790903967.

The spelling of 1999800187 in words is "one billion, nine hundred ninety-nine million, eight hundred thousand, one hundred eighty-seven".