1981188384 has 144 divisors (see below), whose sum is σ = 6213751488. Its totient is φ = 550706688.

The previous prime is 1981188383. The next prime is 1981188397. The reversal of 1981188384 is 4838811891.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1981188383) 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, 168357 + ... + 179739.

It is an arithmetic number, because the mean of its divisors is an integer number (43151052).

Almost surely, 2^1981188384 is an apocalyptic number.

1981188384 is a gapful number since it is divisible by the number (14) 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 1981188384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3106875744).

1981188384 is an abundant number, since it is smaller than the sum of its proper divisors (4232563104).

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

1981188384 is a wasteful number, since it uses less digits than its factorization.

1981188384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11447 (or 11432 counting only the distinct ones).

The product of its digits is 442368, while the sum is 51.

The square root of 1981188384 is about 44510.5423916627. The cubic root of 1981188384 is about 1255.9584080240.

The spelling of 1981188384 in words is "one billion, nine hundred eighty-one million, one hundred eighty-eight thousand, three hundred eighty-four".