21593168 has 40 divisors (see below), whose sum is σ = 43691400. Its totient is φ = 10325504.

The previous prime is 21593167. The next prime is 21593189. The reversal of 21593168 is 86139512.

It can be written as a sum of positive squares in 4 ways, for example, as 2999824 + 18593344 = 1732^2 + 4312^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21593161) 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 7 ways as a sum of consecutive naturals, for example, 80138 + ... + 80406.

It is an arithmetic number, because the mean of its divisors is an integer number (1092285).

Almost surely, 2^21593168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21593168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21845700).

21593168 is an abundant number, since it is smaller than the sum of its proper divisors (22098232).

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

21593168 is a wasteful number, since it uses less digits than its factorization.

21593168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479 (or 473 counting only the distinct ones).

The product of its digits is 12960, while the sum is 35.

The square root of 21593168 is about 4646.8449511470. The cubic root of 21593168 is about 278.4659645733.

The spelling of 21593168 in words is "twenty-one million, five hundred ninety-three thousand, one hundred sixty-eight".