1999917188 has 24 divisors (see below), whose sum is σ = 3587952480. Its totient is φ = 974825280.

The previous prime is 1999917151. The next prime is 1999917221. The reversal of 1999917188 is 8817199991.

It is a self number, because there is not a number n which added to its sum of digits gives 1999917188.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255095 + ... + 262817.

It is an arithmetic number, because the mean of its divisors is an integer number (149498020).

Almost surely, 2^1999917188 is an apocalyptic number.

It is an amenable number.

1999917188 is a deficient number, since it is larger than the sum of its proper divisors (1588035292).

1999917188 is a wasteful number, since it uses less digits than its factorization.

1999917188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9347 (or 9345 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 62.

The square root of 1999917188 is about 44720.4336741047. The cubic root of 1999917188 is about 1259.9036602245.

The spelling of 1999917188 in words is "one billion, nine hundred ninety-nine million, nine hundred seventeen thousand, one hundred eighty-eight".