21115248 has 160 divisors (see below), whose sum is σ = 70709760. Its totient is φ = 5268480.

The previous prime is 21115231. The next prime is 21115249. The reversal of 21115248 is 84251112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107086 + ... + 107282.

It is an arithmetic number, because the mean of its divisors is an integer number (441936).

Almost surely, 2^21115248 is an apocalyptic number.

21115248 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 21115248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35354880).

21115248 is an abundant number, since it is smaller than the sum of its proper divisors (49594512).

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

21115248 is a wasteful number, since it uses less digits than its factorization.

21115248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255 (or 249 counting only the distinct ones).

The product of its digits is 640, while the sum is 24.

The square root of 21115248 is about 4595.1330775071. The cubic root of 21115248 is about 276.3961963757.

The spelling of 21115248 in words is "twenty-one million, one hundred fifteen thousand, two hundred forty-eight".