20805011 has 2 divisors, whose sum is σ = 20805012. Its totient is φ = 20805010.

The previous prime is 20804983. The next prime is 20805017. The reversal of 20805011 is 11050802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20805011 - 2⁶ = 20804947 is a prime.

It is a Chen prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (20805017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10402505 + 10402506.

It is an arithmetic number, because the mean of its divisors is an integer number (10402506).

Almost surely, 2^20805011 is an apocalyptic number.

20805011 is a deficient number, since it is larger than the sum of its proper divisors (1).

20805011 is an equidigital number, since it uses as much as digits as its factorization.

20805011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 20805011 is about 4561.2510345299. The cubic root of 20805011 is about 275.0358564816.

Adding to 20805011 its reverse (11050802), we get a palindrome (31855813).

The spelling of 20805011 in words is "twenty million, eight hundred five thousand, eleven".