21227856 has 40 divisors (see below), whose sum is σ = 59058720. Its totient is φ = 6531456.

The previous prime is 21227851. The next prime is 21227863. The reversal of 21227856 is 65872212.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227851) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 16386 + ... + 17633.

It is an arithmetic number, because the mean of its divisors is an integer number (1476468).

Almost surely, 2^21227856 is an apocalyptic number.

21227856 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21227856 is an abundant number, since it is smaller than the sum of its proper divisors (37830864).

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

21227856 is a wasteful number, since it uses less digits than its factorization.

21227856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34043 (or 34037 counting only the distinct ones).

The product of its digits is 13440, while the sum is 33.

The square root of 21227856 is about 4607.3697485659. The cubic root of 21227856 is about 276.8866674829.

The spelling of 21227856 in words is "twenty-one million, two hundred twenty-seven thousand, eight hundred fifty-six".