20808029 has 4 divisors (see below), whose sum is σ = 22699680. Its totient is φ = 18916380.

The previous prime is 20808019. The next prime is 20808071. The reversal of 20808029 is 92080802.

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 20808029 - 2⁴ = 20808013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20807992 and 20808010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20808019) 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 3 ways as a sum of consecutive naturals, for example, 945809 + ... + 945830.

It is an arithmetic number, because the mean of its divisors is an integer number (5674920).

Almost surely, 2^20808029 is an apocalyptic number.

It is an amenable number.

20808029 is a deficient number, since it is larger than the sum of its proper divisors (1891651).

20808029 is a wasteful number, since it uses less digits than its factorization.

20808029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1891650.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 20808029 is about 4561.5818528225. The cubic root of 20808029 is about 275.0491548497.

The spelling of 20808029 in words is "twenty million, eight hundred eight thousand, twenty-nine".