1999943172 has 72 divisors (see below), whose sum is σ = 5404928256. Its totient is φ = 621321984.

The previous prime is 1999943167. The next prime is 1999943191. The reversal of 1999943172 is 2713499991.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47173 + ... + 78899.

It is an arithmetic number, because the mean of its divisors is an integer number (75068448).

Almost surely, 2^1999943172 is an apocalyptic number.

1999943172 is a gapful number since it is divisible by the number (12) 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 1999943172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2702464128).

1999943172 is an abundant number, since it is smaller than the sum of its proper divisors (3404985084).

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

1999943172 is a wasteful number, since it uses less digits than its factorization.

1999943172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31857 (or 31852 counting only the distinct ones).

The product of its digits is 1102248, while the sum is 54.

The square root of 1999943172 is about 44720.7241891273. The cubic root of 1999943172 is about 1259.9091166496.

The spelling of 1999943172 in words is "one billion, nine hundred ninety-nine million, nine hundred forty-three thousand, one hundred seventy-two".