20808051 has 32 divisors (see below), whose sum is σ = 33177600. Its totient is φ = 11450880.

The previous prime is 20808019. The next prime is 20808071. The reversal of 20808051 is 15080802.

It is not a de Polignac number, because 20808051 - 2⁵ = 20808019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20808071) 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 31 ways as a sum of consecutive naturals, for example, 15630 + ... + 16908.

It is an arithmetic number, because the mean of its divisors is an integer number (1036800).

Almost surely, 2^20808051 is an apocalyptic number.

20808051 is a deficient number, since it is larger than the sum of its proper divisors (12369549).

20808051 is a wasteful number, since it uses less digits than its factorization.

20808051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 20808051 is about 4561.5842642661. The cubic root of 20808051 is about 275.0492517847.

Adding to 20808051 its reverse (15080802), we get a palindrome (35888853).

The spelling of 20808051 in words is "twenty million, eight hundred eight thousand, fifty-one".