1981449216 has 132 divisors (see below), whose sum is σ = 5934040112. Its totient is φ = 660400128.

The previous prime is 1981449203. The next prime is 1981449247. The reversal of 1981449216 is 6129441891.

It is a happy number.

1981449216 is a `hidden beast` number, since 198 + 1 + 449 + 2 + 16 = 666.

It is a super-3 number, since 3×1981449216³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

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, 244851 + ... + 252813.

Almost surely, 2^1981449216 is an apocalyptic number.

1981449216 is a gapful number since it is divisible by the number (16) 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 1981449216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2967020056).

1981449216 is an abundant number, since it is smaller than the sum of its proper divisors (3952590896).

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

1981449216 is an frugal number, since it uses more digits than its factorization.

1981449216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7998 (or 7968 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 1981449216 is about 44513.4722977213. The cubic root of 1981449216 is about 1256.0135230534.

The spelling of 1981449216 in words is "one billion, nine hundred eighty-one million, four hundred forty-nine thousand, two hundred sixteen".