21344512 has 72 divisors (see below), whose sum is σ = 50004416. Its totient is φ = 8902656.

The previous prime is 21344507. The next prime is 21344513. The reversal of 21344512 is 21544312.

It is not an unprimeable number, because it can be changed into a prime (21344513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76918 + ... + 77194.

Almost surely, 2^21344512 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 21344512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25002208).

21344512 is an abundant number, since it is smaller than the sum of its proper divisors (28659904).

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

21344512 is an equidigital number, since it uses as much as digits as its factorization.

21344512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343 (or 329 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21344512 is about 4620.0121211962. The cubic root of 21344512 is about 277.3929441224.

Adding to 21344512 its reverse (21544312), we get a palindrome (42888824).

The spelling of 21344512 in words is "twenty-one million, three hundred forty-four thousand, five hundred twelve".