20705211 has 12 divisors (see below), whose sum is σ = 30354792. Its totient is φ = 13597056.

The previous prime is 20705203. The next prime is 20705261. The reversal of 20705211 is 11250702.

It is not a de Polignac number, because 20705211 - 2³ = 20705203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20705261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16566 + ... + 17771.

It is an arithmetic number, because the mean of its divisors is an integer number (2529566).

Almost surely, 2^20705211 is an apocalyptic number.

20705211 is a deficient number, since it is larger than the sum of its proper divisors (9649581).

20705211 is a wasteful number, since it uses less digits than its factorization.

20705211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34410 (or 34407 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 20705211 is about 4550.2979023356. The cubic root of 20705211 is about 274.5953762952.

Adding to 20705211 its reverse (11250702), we get a palindrome (31955913).

The spelling of 20705211 in words is "twenty million, seven hundred five thousand, two hundred eleven".