19889984 has 14 divisors (see below), whose sum is σ = 39469314. Its totient is φ = 9944960.

The previous prime is 19889981. The next prime is 19890007. The reversal of 19889984 is 48998891.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 529984 = 4400^2 + 728^2 .

It is a super-2 number, since 2×19889984² = 791222927040512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19889981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155327 + ... + 155454.

Almost surely, 2^19889984 is an apocalyptic number.

It is an amenable number.

19889984 is a deficient number, since it is larger than the sum of its proper divisors (19579330).

19889984 is an equidigital number, since it uses as much as digits as its factorization.

19889984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310793 (or 310783 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 56.

The square root of 19889984 is about 4459.8188304011. The cubic root of 19889984 is about 270.9431306348.

The spelling of 19889984 in words is "nineteen million, eight hundred eighty-nine thousand, nine hundred eighty-four".