21138848 has 12 divisors (see below), whose sum is σ = 41617170. Its totient is φ = 10569408.

The previous prime is 21138847. The next prime is 21138851. The reversal of 21138848 is 84883112.

It can be written as a sum of positive squares in only one way, i.e., 12306064 + 8832784 = 3508^2 + 2972^2 .

It is not an unprimeable number, because it can be changed into a prime (21138847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330263 + ... + 330326.

Almost surely, 2^21138848 is an apocalyptic number.

It is an amenable number.

21138848 is a deficient number, since it is larger than the sum of its proper divisors (20478322).

21138848 is an equidigital number, since it uses as much as digits as its factorization.

21138848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660599 (or 660591 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 21138848 is about 4597.7002947126. The cubic root of 21138848 is about 276.4991318083.

The spelling of 21138848 in words is "twenty-one million, one hundred thirty-eight thousand, eight hundred forty-eight".