1981144844 has 24 divisors (see below), whose sum is σ = 4195366560. Its totient is φ = 799117056.

The previous prime is 1981144843. The next prime is 1981144853. The reversal of 1981144844 is 4484411891.

It is a junction number, because it is equal to n+sod(n) for n = 1981144795 and 1981144804.

It is not an unprimeable number, because it can be changed into a prime (1981144843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2080559 + ... + 2081510.

It is an arithmetic number, because the mean of its divisors is an integer number (174806940).

Almost surely, 2^1981144844 is an apocalyptic number.

1981144844 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1981144844 is an abundant number, since it is smaller than the sum of its proper divisors (2214221716).

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

1981144844 is a wasteful number, since it uses less digits than its factorization.

1981144844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4162097 (or 4162095 counting only the distinct ones).

The product of its digits is 147456, while the sum is 44.

The square root of 1981144844 is about 44510.0532913633. The cubic root of 1981144844 is about 1255.9492073459.

The spelling of 1981144844 in words is "one billion, nine hundred eighty-one million, one hundred forty-four thousand, eight hundred forty-four".