21867328 has 84 divisors (see below), whose sum is σ = 53279040. Its totient is φ = 8854272.

The previous prime is 21867317. The next prime is 21867331. The reversal of 21867328 is 82376812.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 59401 + ... + 59767.

Almost surely, 2^21867328 is an apocalyptic number.

21867328 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 21867328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26639520).

21867328 is an abundant number, since it is smaller than the sum of its proper divisors (31411712).

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

21867328 is a wasteful number, since it uses less digits than its factorization.

21867328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412 (or 395 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 21867328 is about 4676.2514902430. The cubic root of 21867328 is about 279.6395361485.

The spelling of 21867328 in words is "twenty-one million, eight hundred sixty-seven thousand, three hundred twenty-eight".