21747056 has 20 divisors (see below), whose sum is σ = 43163904. Its totient is φ = 10608000.

The previous prime is 21747053. The next prime is 21747059. The reversal of 21747056 is 65074712.

It is an interprime number because it is at equal distance from previous prime (21747053) and next prime (21747059).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21747053) by changing a digit.

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, 15920 + ... + 17231.

Almost surely, 2^21747056 is an apocalyptic number.

It is an amenable number.

21747056 is a deficient number, since it is larger than the sum of its proper divisors (21416848).

21747056 is a wasteful number, since it uses less digits than its factorization.

21747056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33200 (or 33194 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21747056 is about 4663.3738859328. The cubic root of 21747056 is about 279.1259136274.

The spelling of 21747056 in words is "twenty-one million, seven hundred forty-seven thousand, fifty-six".