21728852 has 24 divisors (see below), whose sum is σ = 39795840. Its totient is φ = 10370240.

The previous prime is 21728851. The next prime is 21728857. The reversal of 21728852 is 25882712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21728851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6299 + ... + 9117.

It is an arithmetic number, because the mean of its divisors is an integer number (1658160).

Almost surely, 2^21728852 is an apocalyptic number.

It is an amenable number.

21728852 is a deficient number, since it is larger than the sum of its proper divisors (18066988).

21728852 is a wasteful number, since it uses less digits than its factorization.

21728852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2911 (or 2909 counting only the distinct ones).

The product of its digits is 17920, while the sum is 35.

The square root of 21728852 is about 4661.4216715504. The cubic root of 21728852 is about 279.0480084221.

The spelling of 21728852 in words is "twenty-one million, seven hundred twenty-eight thousand, eight hundred fifty-two".