21042048 has 64 divisors (see below), whose sum is σ = 57442320. Its totient is φ = 6819840.

The previous prime is 21042017. The next prime is 21042053. The reversal of 21042048 is 84024012.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13468 + ... + 14948.

Almost surely, 2^21042048 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 21042048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28721160).

21042048 is an abundant number, since it is smaller than the sum of its proper divisors (36400272).

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

21042048 is a wasteful number, since it uses less digits than its factorization.

21042048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 21042048 is about 4587.1612136484. The cubic root of 21042048 is about 276.0764333575.

The spelling of 21042048 in words is "twenty-one million, forty-two thousand, forty-eight".