21845244 has 24 divisors (see below), whose sum is σ = 52350928. Its totient is φ = 7084800.

The previous prime is 21845237. The next prime is 21845249. The reversal of 21845244 is 44254812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21845249) 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, 24157 + ... + 25044.

Almost surely, 2^21845244 is an apocalyptic number.

It is an amenable number.

21845244 is an abundant number, since it is smaller than the sum of its proper divisors (30505684).

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

21845244 is a wasteful number, since it uses less digits than its factorization.

21845244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49245 (or 49243 counting only the distinct ones).

The product of its digits is 10240, while the sum is 30.

The square root of 21845244 is about 4673.8896007501. The cubic root of 21845244 is about 279.5453676611.

The spelling of 21845244 in words is "twenty-one million, eight hundred forty-five thousand, two hundred forty-four".