20709211 has 2 divisors, whose sum is σ = 20709212. Its totient is φ = 20709210.

The previous prime is 20709203. The next prime is 20709217. The reversal of 20709211 is 11290702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20709211 - 2³ = 20709203 is a prime.

It is not a weakly prime, because it can be changed into another prime (20709217) 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 as a sum of consecutive naturals, namely, 10354605 + 10354606.

It is an arithmetic number, because the mean of its divisors is an integer number (10354606).

Almost surely, 2^20709211 is an apocalyptic number.

20709211 is a deficient number, since it is larger than the sum of its proper divisors (1).

20709211 is an equidigital number, since it uses as much as digits as its factorization.

20709211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 20709211 is about 4550.7374127717. The cubic root of 20709211 is about 274.6130580079.

Adding to 20709211 its reverse (11290702), we get a palindrome (31999913).

The spelling of 20709211 in words is "twenty million, seven hundred nine thousand, two hundred eleven".