21048444 has 48 divisors (see below), whose sum is σ = 55283200. Its totient is φ = 6924528.

The previous prime is 21048421. The next prime is 21048451. The reversal of 21048444 is 44484012.

It is a happy number.

21048444 is a `hidden beast` number, since 210 + 4 + 8 + 444 = 666.

It is a super-3 number, since 3×21048444³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7299 + ... + 9765.

Almost surely, 2^21048444 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 21048444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27641600).

21048444 is an abundant number, since it is smaller than the sum of its proper divisors (34234756).

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

21048444 is a wasteful number, since it uses less digits than its factorization.

21048444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2559 (or 2551 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 27.

The square root of 21048444 is about 4587.8583238805. The cubic root of 21048444 is about 276.1044028465.

The spelling of 21048444 in words is "twenty-one million, forty-eight thousand, four hundred forty-four".