21628608 has 56 divisors (see below), whose sum is σ = 57741312. Its totient is φ = 7144704.

The previous prime is 21628603. The next prime is 21628627. The reversal of 21628608 is 80682612.

It is not an unprimeable number, because it can be changed into a prime (21628603) 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, 23941 + ... + 24827.

Almost surely, 2^21628608 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 21628608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28870656).

21628608 is an abundant number, since it is smaller than the sum of its proper divisors (36112704).

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

21628608 is a wasteful number, since it uses less digits than its factorization.

21628608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029 (or 1019 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 21628608 is about 4650.6567278181. The cubic root of 21628608 is about 278.6182263072.

The spelling of 21628608 in words is "twenty-one million, six hundred twenty-eight thousand, six hundred eight".