19981384 has 8 divisors (see below), whose sum is σ = 37465110. Its totient is φ = 9990688.

The previous prime is 19981373. The next prime is 19981397. The reversal of 19981384 is 48318991.

It can be written as a sum of positive squares in only one way, i.e., 19980900 + 484 = 4470^2 + 22^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 19981384.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1248829 + ... + 1248844.

Almost surely, 2^19981384 is an apocalyptic number.

It is an amenable number.

19981384 is a deficient number, since it is larger than the sum of its proper divisors (17483726).

19981384 is a wasteful number, since it uses less digits than its factorization.

19981384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2497679 (or 2497675 counting only the distinct ones).

The product of its digits is 62208, while the sum is 43.

The square root of 19981384 is about 4470.0541383746. The cubic root of 19981384 is about 271.3575161849.

The spelling of 19981384 in words is "nineteen million, nine hundred eighty-one thousand, three hundred eighty-four".