21344928 has 192 divisors, whose sum is σ = 68584320. Its totient is φ = 5734400.

The previous prime is 21344903. The next prime is 21344929. The reversal of 21344928 is 82944312.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21344929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 520588 + ... + 520628.

It is an arithmetic number, because the mean of its divisors is an integer number (357210).

Almost surely, 2^21344928 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 21344928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34292160).

21344928 is an abundant number, since it is smaller than the sum of its proper divisors (47239392).

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

21344928 is a wasteful number, since it uses less digits than its factorization.

21344928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 103 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21344928 is about 4620.0571425038. The cubic root of 21344928 is about 277.3947462205.

The spelling of 21344928 in words is "twenty-one million, three hundred forty-four thousand, nine hundred twenty-eight".