21004876 has 12 divisors (see below), whose sum is σ = 36809640. Its totient is φ = 10487840.

The previous prime is 21004847. The next prime is 21004883. The reversal of 21004876 is 67840012.

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, 10 + ... + 6481.

It is an arithmetic number, because the mean of its divisors is an integer number (3067470).

Almost surely, 2^21004876 is an apocalyptic number.

It is an amenable number.

21004876 is a deficient number, since it is larger than the sum of its proper divisors (15804764).

21004876 is a wasteful number, since it uses less digits than its factorization.

21004876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7304 (or 7302 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21004876 is about 4583.1076792936. The cubic root of 21004876 is about 275.9137691829.

Adding to 21004876 its reverse (67840012), we get a palindrome (88844888).

The spelling of 21004876 in words is "twenty-one million, four thousand, eight hundred seventy-six".