21847872 has 112 divisors (see below), whose sum is σ = 62544960. Its totient is φ = 6709248.

The previous prime is 21847867. The next prime is 21847879. The reversal of 21847872 is 27874812.

It is a self number, because there is not a number n which added to its sum of digits gives 21847872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21847879) 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, 193288 + ... + 193400.

Almost surely, 2^21847872 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 21847872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31272480).

21847872 is an abundant number, since it is smaller than the sum of its proper divisors (40697088).

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

21847872 is a wasteful number, since it uses less digits than its factorization.

21847872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 190 counting only the distinct ones).

The product of its digits is 50176, while the sum is 39.

The square root of 21847872 is about 4674.1707285892. The cubic root of 21847872 is about 279.5565770540.

The spelling of 21847872 in words is "twenty-one million, eight hundred forty-seven thousand, eight hundred seventy-two".