21084168 has 64 divisors (see below), whose sum is σ = 61729920. Its totient is φ = 5875200.

The previous prime is 21084139. The next prime is 21084187. The reversal of 21084168 is 86148012.

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, 5358 + ... + 8418.

It is an arithmetic number, because the mean of its divisors is an integer number (964530).

Almost surely, 2^21084168 is an apocalyptic number.

21084168 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 21084168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30864960).

21084168 is an abundant number, since it is smaller than the sum of its proper divisors (40645752).

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

21084168 is a wasteful number, since it uses less digits than its factorization.

21084168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118 (or 3114 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 21084168 is about 4591.7499931943. The cubic root of 21084168 is about 276.2605185624.

The spelling of 21084168 in words is "twenty-one million, eighty-four thousand, one hundred sixty-eight".