20129128 has 16 divisors (see below), whose sum is σ = 37940580. Its totient is φ = 10011648.

The previous prime is 20129111. The next prime is 20129129. The reversal of 20129128 is 82192102.

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 40804 = 4482^2 + 202^2 .

It is not an unprimeable number, because it can be changed into a prime (20129129) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 4975 + ... + 8062.

Almost surely, 2^20129128 is an apocalyptic number.

It is an amenable number.

20129128 is a deficient number, since it is larger than the sum of its proper divisors (17811452).

20129128 is a wasteful number, since it uses less digits than its factorization.

20129128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13236 (or 13232 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20129128 is about 4486.5496765332. The cubic root of 20129128 is about 272.0246877822.

The spelling of 20129128 in words is "twenty million, one hundred twenty-nine thousand, one hundred twenty-eight".