21526648 has 64 divisors (see below), whose sum is σ = 49029120. Its totient is φ = 8726400.

The previous prime is 21526633. The next prime is 21526649. The reversal of 21526648 is 84662512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21526649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35161 + ... + 35767.

It is an arithmetic number, because the mean of its divisors is an integer number (766080).

Almost surely, 2^21526648 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 21526648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24514560).

21526648 is an abundant number, since it is smaller than the sum of its proper divisors (27502472).

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

21526648 is a wasteful number, since it uses less digits than its factorization.

21526648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668 (or 664 counting only the distinct ones).

The product of its digits is 23040, while the sum is 34.

The square root of 21526648 is about 4639.6818856469. The cubic root of 21526648 is about 278.1797226498.

The spelling of 21526648 in words is "twenty-one million, five hundred twenty-six thousand, six hundred forty-eight".