21045828 has 24 divisors (see below), whose sum is σ = 51242688. Its totient is φ = 6710176.

The previous prime is 21045811. The next prime is 21045853. The reversal of 21045828 is 82854012.

It is a junction number, because it is equal to n+sod(n) for n = 21045795 and 21045804.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 37851 + ... + 38402.

It is an arithmetic number, because the mean of its divisors is an integer number (2135112).

Almost surely, 2^21045828 is an apocalyptic number.

It is an amenable number.

21045828 is an abundant number, since it is smaller than the sum of its proper divisors (30196860).

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

21045828 is a wasteful number, since it uses less digits than its factorization.

21045828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76283 (or 76281 counting only the distinct ones).

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

The square root of 21045828 is about 4587.5732146746. The cubic root of 21045828 is about 276.0929638530.

The spelling of 21045828 in words is "twenty-one million, forty-five thousand, eight hundred twenty-eight".