20028636 has 18 divisors (see below), whose sum is σ = 50628032. Its totient is φ = 6676200.

The previous prime is 20028629. The next prime is 20028637. The reversal of 20028636 is 63682002.

20028636 is a `hidden beast` number, since 2 + 0 + 0 + 28 + 636 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×20028636² = 802292520040992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20028637) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 278140 + ... + 278211.

Almost surely, 2^20028636 is an apocalyptic number.

It is an amenable number.

20028636 is an abundant number, since it is smaller than the sum of its proper divisors (30599396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20028636 is a wasteful number, since it uses less digits than its factorization.

20028636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556361 (or 556356 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20028636 is about 4475.3364119360. The cubic root of 20028636 is about 271.5712499835.

The spelling of 20028636 in words is "twenty million, twenty-eight thousand, six hundred thirty-six".