21450828 has 54 divisors (see below), whose sum is σ = 58530108. Its totient is φ = 6096720.

The previous prime is 21450827. The next prime is 21450839. The reversal of 21450828 is 82805412.

It is a junction number, because it is equal to n+sod(n) for n = 21450795 and 21450804.

It is not an unprimeable number, because it can be changed into a prime (21450827) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 112213 + ... + 112403.

Almost surely, 2^21450828 is an apocalyptic number.

21450828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21450828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29265054).

21450828 is an abundant number, since it is smaller than the sum of its proper divisors (37079280).

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

21450828 is a wasteful number, since it uses less digits than its factorization.

21450828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 203 counting only the distinct ones).

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

The square root of 21450828 is about 4631.5038594392. The cubic root of 21450828 is about 277.8527419127.

The spelling of 21450828 in words is "twenty-one million, four hundred fifty thousand, eight hundred twenty-eight".