20205129 has 16 divisors (see below), whose sum is σ = 32600448. Its totient is φ = 10866432.

The previous prime is 20205121. The next prime is 20205139. The reversal of 20205129 is 92150202.

It is not a de Polignac number, because 20205129 - 2³ = 20205121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20205121) 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 15 ways as a sum of consecutive naturals, for example, 27942 + ... + 28655.

It is an arithmetic number, because the mean of its divisors is an integer number (2037528).

Almost surely, 2^20205129 is an apocalyptic number.

It is an amenable number.

20205129 is a deficient number, since it is larger than the sum of its proper divisors (12395319).

20205129 is a wasteful number, since it uses less digits than its factorization.

20205129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56624.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20205129 is about 4495.0115683945. The cubic root of 20205129 is about 272.3666165389.

The spelling of 20205129 in words is "twenty million, two hundred five thousand, one hundred twenty-nine".