21872448 has 168 divisors, whose sum is σ = 71006208. Its totient is φ = 6386688.

The previous prime is 21872447. The next prime is 21872449. The reversal of 21872448 is 84427812.

It is an interprime number because it is at equal distance from previous prime (21872447) and next prime (21872449).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21872441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 172161 + ... + 172287.

It is an arithmetic number, because the mean of its divisors is an integer number (422656).

Almost surely, 2^21872448 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 21872448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35503104).

21872448 is an abundant number, since it is smaller than the sum of its proper divisors (49133760).

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

21872448 is a wasteful number, since it uses less digits than its factorization.

21872448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 168 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 21872448 is about 4676.7989052342. The cubic root of 21872448 is about 279.6613593100.

The spelling of 21872448 in words is "twenty-one million, eight hundred seventy-two thousand, four hundred forty-eight".