1999943173 has 16 divisors (see below), whose sum is σ = 2203816320. Its totient is φ = 1806463296.

The previous prime is 1999943167. The next prime is 1999943191. The reversal of 1999943173 is 3713499991.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1999943173 - 2⁹ = 1999942661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999943273) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131311 + ... + 145747.

It is an arithmetic number, because the mean of its divisors is an integer number (137738520).

Almost surely, 2^1999943173 is an apocalyptic number.

It is an amenable number.

1999943173 is a deficient number, since it is larger than the sum of its proper divisors (203873147).

1999943173 is a wasteful number, since it uses less digits than its factorization.

1999943173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14796.

The product of its digits is 1653372, while the sum is 55.

The square root of 1999943173 is about 44720.7242003078. The cubic root of 1999943173 is about 1259.9091168596.

The spelling of 1999943173 in words is "one billion, nine hundred ninety-nine million, nine hundred forty-three thousand, one hundred seventy-three".