220971728 has 20 divisors (see below), whose sum is σ = 430701600. Its totient is φ = 109822944.

The previous prime is 220971713. The next prime is 220971731. The reversal of 220971728 is 827179022.

It is a junction number, because it is equal to n+sod(n) for n = 220971691 and 220971700.

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 in 3 ways as a sum of consecutive naturals, for example, 38678 + ... + 44021.

It is an arithmetic number, because the mean of its divisors is an integer number (21535080).

Almost surely, 2^220971728 is an apocalyptic number.

It is an amenable number.

220971728 is a deficient number, since it is larger than the sum of its proper divisors (209729872).

220971728 is a wasteful number, since it uses less digits than its factorization.

220971728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82874 (or 82868 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 220971728 is about 14865.1178266437. The cubic root of 220971728 is about 604.5685770663.

It can be divided in two parts, 2209 and 71728, that added together give a palindrome (73937).

The spelling of 220971728 in words is "two hundred twenty million, nine hundred seventy-one thousand, seven hundred twenty-eight".