21248416 has 48 divisors (see below), whose sum is σ = 49472640. Its totient is φ = 8789760.

The previous prime is 21248411. The next prime is 21248417. The reversal of 21248416 is 61484212.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21248411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4861 + ... + 8131.

It is an arithmetic number, because the mean of its divisors is an integer number (1030680).

Almost surely, 2^21248416 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 21248416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24736320).

21248416 is an abundant number, since it is smaller than the sum of its proper divisors (28224224).

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

21248416 is a wasteful number, since it uses less digits than its factorization.

21248416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3317 (or 3309 counting only the distinct ones).

The product of its digits is 3072, while the sum is 28.

The square root of 21248416 is about 4609.6004165220. The cubic root of 21248416 is about 276.9760304560.

The spelling of 21248416 in words is "twenty-one million, two hundred forty-eight thousand, four hundred sixteen".