21728876 has 12 divisors (see below), whose sum is σ = 40950672. Its totient is φ = 10028688.

The previous prime is 21728867. The next prime is 21728891. The reversal of 21728876 is 67882712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208880 + ... + 208983.

It is an arithmetic number, because the mean of its divisors is an integer number (3412556).

Almost surely, 2^21728876 is an apocalyptic number.

21728876 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21728876 is a deficient number, since it is larger than the sum of its proper divisors (19221796).

21728876 is a wasteful number, since it uses less digits than its factorization.

21728876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417880 (or 417878 counting only the distinct ones).

The product of its digits is 75264, while the sum is 41.

The square root of 21728876 is about 4661.4242458716. The cubic root of 21728876 is about 279.0481111603.

The spelling of 21728876 in words is "twenty-one million, seven hundred twenty-eight thousand, eight hundred seventy-six".