21535248 has 80 divisors (see below), whose sum is σ = 64281600. Its totient is φ = 6085248.

The previous prime is 21535247. The next prime is 21535253. The reversal of 21535248 is 84253512.

It is not an unprimeable number, because it can be changed into a prime (21535247) 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, 35653 + ... + 36251.

It is an arithmetic number, because the mean of its divisors is an integer number (803520).

Almost surely, 2^21535248 is an apocalyptic number.

21535248 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21535248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32140800).

21535248 is an abundant number, since it is smaller than the sum of its proper divisors (42746352).

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

21535248 is a wasteful number, since it uses less digits than its factorization.

21535248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 718 counting only the distinct ones).

The product of its digits is 9600, while the sum is 30.

The square root of 21535248 is about 4640.6085807790. The cubic root of 21535248 is about 278.2167624326.

The spelling of 21535248 in words is "twenty-one million, five hundred thirty-five thousand, two hundred forty-eight".