1881728784 has 120 divisors (see below), whose sum is σ = 5809883352. Its totient is φ = 564848640.

The previous prime is 1881728747. The next prime is 1881728789. The reversal of 1881728784 is 4878271881.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 102576384 + 1779152400 = 10128^2 + 42180^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1881728784.

It is not an unprimeable number, because it can be changed into a prime (1881728789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64494 + ... + 89010.

Almost surely, 2^1881728784 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 1881728784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2904941676).

1881728784 is an abundant number, since it is smaller than the sum of its proper divisors (3928154568).

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

1881728784 is a wasteful number, since it uses less digits than its factorization.

1881728784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24585 (or 24576 counting only the distinct ones).

The product of its digits is 1605632, while the sum is 54.

The square root of 1881728784 is about 43378.8979113117. The cubic root of 1881728784 is about 1234.5793524443.

The spelling of 1881728784 in words is "one billion, eight hundred eighty-one million, seven hundred twenty-eight thousand, seven hundred eighty-four".