20210728 has 32 divisors (see below), whose sum is σ = 38851200. Its totient is φ = 9854208.

The previous prime is 20210717. The next prime is 20210747. The reversal of 20210728 is 82701202.

It is a junction number, because it is equal to n+sod(n) for n = 20210699 and 20210708.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71275 + ... + 71557.

It is an arithmetic number, because the mean of its divisors is an integer number (1214100).

Almost surely, 2^20210728 is an apocalyptic number.

It is an amenable number.

20210728 is a deficient number, since it is larger than the sum of its proper divisors (18640472).

20210728 is a wasteful number, since it uses less digits than its factorization.

20210728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 20210728 is about 4495.6343267664. The cubic root of 20210728 is about 272.3917725253.

The spelling of 20210728 in words is "twenty million, two hundred ten thousand, seven hundred twenty-eight".