21283648 has 56 divisors (see below), whose sum is σ = 46451520. Its totient is φ = 9630720.

The previous prime is 21283597. The next prime is 21283657. The reversal of 21283648 is 84638212.

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, 27588 + ... + 28348.

Almost surely, 2^21283648 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 21283648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23225760).

21283648 is an abundant number, since it is smaller than the sum of its proper divisors (25167872).

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

21283648 is a wasteful number, since it uses less digits than its factorization.

21283648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815 (or 805 counting only the distinct ones).

The product of its digits is 18432, while the sum is 34.

The square root of 21283648 is about 4613.4204230701. The cubic root of 21283648 is about 277.1290305822.

It can be divided in two parts, 2128 and 3648, that added together give a square (5776 = 76²).

The spelling of 21283648 in words is "twenty-one million, two hundred eighty-three thousand, six hundred forty-eight".