21253248 has 96 divisors (see below), whose sum is σ = 64443600. Its totient is φ = 6704640.

The previous prime is 21253241. The next prime is 21253277. The reversal of 21253248 is 84235212.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21253241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21403 + ... + 22373.

Almost surely, 2^21253248 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 21253248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32221800).

21253248 is an abundant number, since it is smaller than the sum of its proper divisors (43190352).

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

21253248 is a wasteful number, since it uses less digits than its factorization.

21253248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010 (or 995 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21253248 is about 4610.1245102492. The cubic root of 21253248 is about 276.9970241266.

The spelling of 21253248 in words is "twenty-one million, two hundred fifty-three thousand, two hundred forty-eight".