19988864 has 48 divisors (see below), whose sum is σ = 46337580. Its totient is φ = 8563968.

The previous prime is 19988849. The next prime is 19988867. The reversal of 19988864 is 46888991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19988867) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4679 + ... + 7865.

Almost surely, 2^19988864 is an apocalyptic number.

19988864 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 19988864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23168790).

19988864 is an abundant number, since it is smaller than the sum of its proper divisors (26348716).

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

19988864 is an equidigital number, since it uses as much as digits as its factorization.

19988864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3215 (or 3196 counting only the distinct ones).

The product of its digits is 995328, while the sum is 53.

The square root of 19988864 is about 4470.8907389915. The cubic root of 19988864 is about 271.3913727152.

The spelling of 19988864 in words is "nineteen million, nine hundred eighty-eight thousand, eight hundred sixty-four".