21142528 has 44 divisors (see below), whose sum is σ = 46131192. Its totient is φ = 9605120.

The previous prime is 21142493. The next prime is 21142529. The reversal of 21142528 is 82524112.

It is a tau number, because it is divible by the number of its divisors (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10326 + ... + 12202.

Almost surely, 2^21142528 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 21142528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23065596).

21142528 is an abundant number, since it is smaller than the sum of its proper divisors (24988664).

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

21142528 is a wasteful number, since it uses less digits than its factorization.

21142528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1908 (or 1890 counting only the distinct ones).

The product of its digits is 1280, while the sum is 25.

The square root of 21142528 is about 4598.1004773711. The cubic root of 21142528 is about 276.5151758514.

The spelling of 21142528 in words is "twenty-one million, one hundred forty-two thousand, five hundred twenty-eight".