20285128 has 8 divisors (see below), whose sum is σ = 38034630. Its totient is φ = 10142560.

The previous prime is 20285099. The next prime is 20285263. The reversal of 20285128 is 82158202.

It can be written as a sum of positive squares in only one way, i.e., 13410244 + 6874884 = 3662^2 + 2622^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×20285128² = 822972835952768, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20285096 and 20285105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1267813 + ... + 1267828.

Almost surely, 2^20285128 is an apocalyptic number.

It is an amenable number.

20285128 is a deficient number, since it is larger than the sum of its proper divisors (17749502).

20285128 is a wasteful number, since it uses less digits than its factorization.

20285128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2535647 (or 2535643 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 20285128 is about 4503.9014198803. The cubic root of 20285128 is about 272.7256072895.

The spelling of 20285128 in words is "twenty million, two hundred eighty-five thousand, one hundred twenty-eight".