21728752 has 10 divisors (see below), whose sum is σ = 42099488. Its totient is φ = 10864368.

The previous prime is 21728747. The next prime is 21728789. The reversal of 21728752 is 25782712.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 679008 + ... + 679039.

Almost surely, 2^21728752 is an apocalyptic number.

It is an amenable number.

21728752 is a deficient number, since it is larger than the sum of its proper divisors (20370736).

21728752 is a wasteful number, since it uses less digits than its factorization.

21728752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358055 (or 1358049 counting only the distinct ones).

The product of its digits is 15680, while the sum is 34.

The square root of 21728752 is about 4661.4109451967. The cubic root of 21728752 is about 279.0475803455.

The spelling of 21728752 in words is "twenty-one million, seven hundred twenty-eight thousand, seven hundred fifty-two".