1981440000 has 420 divisors, whose sum is σ = 7318810356. Its totient is φ = 516096000.

The previous prime is 1981439983. The next prime is 1981440037. The reversal of 1981440000 is 441891.

It is a super-3 number, since 3×1981440000³ (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 an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 46079979 + ... + 46080021.

Almost surely, 2^1981440000 is an apocalyptic number.

1981440000 is a gapful number since it is divisible by the number (10) 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 1981440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3659405178).

1981440000 is an abundant number, since it is smaller than the sum of its proper divisors (5337370356).

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

1981440000 is an frugal number, since it uses more digits than its factorization.

1981440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1981440000 is about 44513.3687783794. The cubic root of 1981440000 is about 1256.0115757517.

Adding to 1981440000 its reverse (441891), we get a palindrome (1981881891).

The spelling of 1981440000 in words is "one billion, nine hundred eighty-one million, four hundred forty thousand".