21005848 has 16 divisors (see below), whose sum is σ = 40656960. Its totient is φ = 10164000.

The previous prime is 21005837. The next prime is 21005857. The reversal of 21005848 is 84850012.

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 3 ways as a sum of consecutive naturals, for example, 42103 + ... + 42598.

It is an arithmetic number, because the mean of its divisors is an integer number (2541060).

Almost surely, 2^21005848 is an apocalyptic number.

It is an amenable number.

21005848 is a deficient number, since it is larger than the sum of its proper divisors (19651112).

21005848 is a wasteful number, since it uses less digits than its factorization.

21005848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84738 (or 84734 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 21005848 is about 4583.2137196513. The cubic root of 21005848 is about 275.9180250844.

The spelling of 21005848 in words is "twenty-one million, five thousand, eight hundred forty-eight".