21282528 has 48 divisors (see below), whose sum is σ = 56560896. Its totient is φ = 7006080.

The previous prime is 21282517. The next prime is 21282529. The reversal of 21282528 is 82528212.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 21282495 and 21282504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282529) 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, 6633 + ... + 9303.

It is an arithmetic number, because the mean of its divisors is an integer number (1178352).

Almost surely, 2^21282528 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 21282528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28280448).

21282528 is an abundant number, since it is smaller than the sum of its proper divisors (35278368).

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

21282528 is a wasteful number, since it uses less digits than its factorization.

21282528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767 (or 2759 counting only the distinct ones).

The product of its digits is 5120, while the sum is 30.

The square root of 21282528 is about 4613.2990364814. The cubic root of 21282528 is about 277.1241694174.

It can be divided in two parts, 2128 and 2528, that added together give a triangular number (4656 = T₉₆).

The spelling of 21282528 in words is "twenty-one million, two hundred eighty-two thousand, five hundred twenty-eight".