21803168 has 36 divisors (see below), whose sum is σ = 44416890. Its totient is φ = 10535040.

The previous prime is 21803167. The next prime is 21803179. The reversal of 21803168 is 86130812.

It can be written as a sum of positive squares in only one way, i.e., 21049744 + 753424 = 4588^2 + 868^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21803168.

It is not an unprimeable number, because it can be changed into a prime (21803167) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 30398 + ... + 31106.

Almost surely, 2^21803168 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 21803168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22208445).

21803168 is an abundant number, since it is smaller than the sum of its proper divisors (22613722).

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

21803168 is an equidigital number, since it uses as much as digits as its factorization.

21803168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781 (or 742 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 21803168 is about 4669.3862551732. The cubic root of 21803168 is about 279.3657753945.

The spelling of 21803168 in words is "twenty-one million, eight hundred three thousand, one hundred sixty-eight".