19889920 has 72 divisors (see below), whose sum is σ = 48933360. Its totient is φ = 7741440.

The previous prime is 19889899. The next prime is 19889923. The reversal of 19889920 is 2998891.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19889923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52291 + ... + 52669.

It is an arithmetic number, because the mean of its divisors is an integer number (679630).

Almost surely, 2^19889920 is an apocalyptic number.

19889920 is a gapful number since it is divisible by the number (10) 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 19889920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24466680).

19889920 is an abundant number, since it is smaller than the sum of its proper divisors (29043440).

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

19889920 is an equidigital number, since it uses as much as digits as its factorization.

19889920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 19889920 is about 4459.8116552159. The cubic root of 19889920 is about 270.9428400299.

The spelling of 19889920 in words is "nineteen million, eight hundred eighty-nine thousand, nine hundred twenty".