21523248 has 60 divisors (see below), whose sum is σ = 60730488. Its totient is φ = 7115520.

The previous prime is 21523171. The next prime is 21523261. The reversal of 21523248 is 84232512.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 9.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19183 + ... + 20273.

Almost surely, 2^21523248 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 21523248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30365244).

21523248 is an abundant number, since it is smaller than the sum of its proper divisors (39207240).

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

21523248 is a wasteful number, since it uses less digits than its factorization.

21523248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242 (or 1233 counting only the distinct ones).

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

The square root of 21523248 is about 4639.3154667472. The cubic root of 21523248 is about 278.1650762937.

The spelling of 21523248 in words is "twenty-one million, five hundred twenty-three thousand, two hundred forty-eight".