21068208 has 80 divisors (see below), whose sum is σ = 69122560. Its totient is φ = 6018624.

The previous prime is 21068183. The next prime is 21068209. The reversal of 21068208 is 80286012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21068209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 460 + ... + 6507.

It is an arithmetic number, because the mean of its divisors is an integer number (864032).

Almost surely, 2^21068208 is an apocalyptic number.

21068208 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 21068208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34561280).

21068208 is an abundant number, since it is smaller than the sum of its proper divisors (48054352).

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

21068208 is a wasteful number, since it uses less digits than its factorization.

21068208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6991 (or 6979 counting only the distinct ones).

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

The square root of 21068208 is about 4590.0117646908. The cubic root of 21068208 is about 276.1907943525.

The spelling of 21068208 in words is "twenty-one million, sixty-eight thousand, two hundred eight".