19921344 has 56 divisors (see below), whose sum is σ = 54425088. Its totient is φ = 6424320.

The previous prime is 19921337. The next prime is 19921357. The reversal of 19921344 is 44312991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4279 + ... + 7625.

Almost surely, 2^19921344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19921344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27212544).

19921344 is an abundant number, since it is smaller than the sum of its proper divisors (34503744).

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

19921344 is a wasteful number, since it uses less digits than its factorization.

19921344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3393 (or 3383 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 19921344 is about 4463.3332835449. Note that the first 3 decimals coincide. The cubic root of 19921344 is about 271.0854520990.

The spelling of 19921344 in words is "nineteen million, nine hundred twenty-one thousand, three hundred forty-four".