21503248 has 40 divisors (see below), whose sum is σ = 45566528. Its totient is φ = 9770112.

The previous prime is 21503227. The next prime is 21503263. The reversal of 21503248 is 84230512.

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13165 + ... + 14707.

Almost surely, 2^21503248 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 21503248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22783264).

21503248 is an abundant number, since it is smaller than the sum of its proper divisors (24063280).

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

21503248 is a wasteful number, since it uses less digits than its factorization.

21503248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631 (or 1625 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 21503248 is about 4637.1594753685. The cubic root of 21503248 is about 278.0788900203.

The spelling of 21503248 in words is "twenty-one million, five hundred three thousand, two hundred forty-eight".