21571248 has 80 divisors (see below), whose sum is σ = 58183776. Its totient is φ = 6881280.

The previous prime is 21571243. The next prime is 21571267. The reversal of 21571248 is 84217512.

It is not an unprimeable number, because it can be changed into a prime (21571241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190840 + ... + 190952.

Almost surely, 2^21571248 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 21571248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29091888).

21571248 is an abundant number, since it is smaller than the sum of its proper divisors (36612528).

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

21571248 is a wasteful number, since it uses less digits than its factorization.

21571248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 256 counting only the distinct ones).

The product of its digits is 4480, while the sum is 30.

The square root of 21571248 is about 4644.4857627083. The cubic root of 21571248 is about 278.3717057386.

The spelling of 21571248 in words is "twenty-one million, five hundred seventy-one thousand, two hundred forty-eight".