1999172108 has 12 divisors (see below), whose sum is σ = 3499086360. Its totient is φ = 999433152.

The previous prime is 1999172099. The next prime is 1999172111. The reversal of 1999172108 is 8012719991.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5741 + ... + 63492.

It is an arithmetic number, because the mean of its divisors is an integer number (291590530).

Almost surely, 2^1999172108 is an apocalyptic number.

It is an amenable number.

1999172108 is a deficient number, since it is larger than the sum of its proper divisors (1499914252).

1999172108 is a wasteful number, since it uses less digits than its factorization.

1999172108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76456 (or 76454 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 47.

The square root of 1999172108 is about 44712.1024779645. The cubic root of 1999172108 is about 1259.7471794754.

The spelling of 1999172108 in words is "one billion, nine hundred ninety-nine million, one hundred seventy-two thousand, one hundred eight".