1981998216 has 96 divisors (see below), whose sum is σ = 5895040320. Its totient is φ = 596592000.

The previous prime is 1981998211. The next prime is 1981998217. The reversal of 1981998216 is 6128991891.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1981998211) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 111306 + ... + 127878.

It is an arithmetic number, because the mean of its divisors is an integer number (61406670).

Almost surely, 2^1981998216 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 1981998216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2947520160).

1981998216 is an abundant number, since it is smaller than the sum of its proper divisors (3913042104).

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

1981998216 is a wasteful number, since it uses less digits than its factorization.

1981998216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16747 (or 16740 counting only the distinct ones).

The product of its digits is 559872, while the sum is 54.

The square root of 1981998216 is about 44519.6385430071. The cubic root of 1981998216 is about 1256.1295135355.

The spelling of 1981998216 in words is "one billion, nine hundred eighty-one million, nine hundred ninety-eight thousand, two hundred sixteen".