211009811 has 2 divisors, whose sum is σ = 211009812. Its totient is φ = 211009810.

The previous prime is 211009781. The next prime is 211009819. The reversal of 211009811 is 118900112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211009811 - 2²⁶ = 143900947 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (211009819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105504905 + 105504906.

It is an arithmetic number, because the mean of its divisors is an integer number (105504906).

Almost surely, 2^211009811 is an apocalyptic number.

211009811 is a deficient number, since it is larger than the sum of its proper divisors (1).

211009811 is an equidigital number, since it uses as much as digits as its factorization.

211009811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 211009811 is about 14526.1767509555. The cubic root of 211009811 is about 595.3434083805.

Adding to 211009811 its reverse (118900112), we get a palindrome (329909923).

The spelling of 211009811 in words is "two hundred eleven million, nine thousand, eight hundred eleven".