21028608 has 54 divisors (see below), whose sum is σ = 60637304. Its totient is φ = 7008768.

The previous prime is 21028597. The next prime is 21028619. The reversal of 21028608 is 80682012.

It is an interprime number because it is at equal distance from previous prime (21028597) and next prime (21028619).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2260 + ... + 6867.

Almost surely, 2^21028608 is an apocalyptic number.

It is an amenable number.

21028608 is an abundant number, since it is smaller than the sum of its proper divisors (39608696).

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

21028608 is an equidigital number, since it uses as much as digits as its factorization.

21028608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9149 (or 9132 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21028608 is about 4585.6960213254. The cubic root of 21028608 is about 276.0176422245.

The spelling of 21028608 in words is "twenty-one million, twenty-eight thousand, six hundred eight".