21026208 has 96 divisors (see below), whose sum is σ = 64157184. Its totient is φ = 5905152.

The previous prime is 21026197. The next prime is 21026231. The reversal of 21026208 is 80262012.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44791 + ... + 45257.

It is an arithmetic number, because the mean of its divisors is an integer number (668304).

Almost surely, 2^21026208 is an apocalyptic number.

21026208 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 21026208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32078592).

21026208 is an abundant number, since it is smaller than the sum of its proper divisors (43130976).

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

21026208 is a wasteful number, since it uses less digits than its factorization.

21026208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21026208 is about 4585.4343305733. The cubic root of 21026208 is about 276.0071411721.

The spelling of 21026208 in words is "twenty-one million, twenty-six thousand, two hundred eight".