1999640216 has 48 divisors (see below), whose sum is σ = 4385712240. Its totient is φ = 852223680.

The previous prime is 1999640191. The next prime is 1999640243. The reversal of 1999640216 is 6120469991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56861 + ... + 85043.

It is an arithmetic number, because the mean of its divisors is an integer number (91369005).

Almost surely, 2^1999640216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999640216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2192856120).

1999640216 is an abundant number, since it is smaller than the sum of its proper divisors (2386072024).

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

1999640216 is a wasteful number, since it uses less digits than its factorization.

1999640216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28384 (or 28373 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 1999640216 is about 44717.3368616692. The cubic root of 1999640216 is about 1259.8454954583.

The spelling of 1999640216 in words is "one billion, nine hundred ninety-nine million, six hundred forty thousand, two hundred sixteen".