1981444608 has 480 divisors, whose sum is σ = 7006551552. Its totient is φ = 530841600.

The previous prime is 1981444607. The next prime is 1981444627. The reversal of 1981444608 is 8064441891.

1981444608 is a `hidden beast` number, since 198 + 14 + 446 + 0 + 8 = 666.

It is a super-3 number, since 3×1981444608³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981444607) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20427216 + ... + 20427312.

Almost surely, 2^1981444608 is an apocalyptic number.

1981444608 is a gapful number since it is divisible by the number (18) 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 1981444608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3503275776).

1981444608 is an abundant number, since it is smaller than the sum of its proper divisors (5025106944).

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

1981444608 is a wasteful number, since it uses less digits than its factorization.

1981444608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 1981444608 is about 44513.4205380804. The cubic root of 1981444608 is about 1256.0125494033.

The spelling of 1981444608 in words is "one billion, nine hundred eighty-one million, four hundred forty-four thousand, six hundred eight".