20804129 has 4 divisors (see below), whose sum is σ = 20861184. Its totient is φ = 20747076.

The previous prime is 20804123. The next prime is 20804137. The reversal of 20804129 is 92140802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20804129 - 2¹² = 20800033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20804098 and 20804107.

It is not an unprimeable number, because it can be changed into a prime (20804123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27977 + ... + 28710.

It is an arithmetic number, because the mean of its divisors is an integer number (5215296).

Almost surely, 2^20804129 is an apocalyptic number.

It is an amenable number.

20804129 is a deficient number, since it is larger than the sum of its proper divisors (57055).

20804129 is an equidigital number, since it uses as much as digits as its factorization.

20804129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57054.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20804129 is about 4561.1543495041. The cubic root of 20804129 is about 275.0319698370.

The spelling of 20804129 in words is "twenty million, eight hundred four thousand, one hundred twenty-nine".