1211111211 has 8 divisors (see below), whose sum is σ = 1652368960. Its totient is φ = 788630472.

The previous prime is 1211111201. The next prime is 1211111249. The reversal of 1211111211 is 1121111121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1211111211 - 2¹⁷ = 1210980139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211111201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4694101 + ... + 4694358.

It is an arithmetic number, because the mean of its divisors is an integer number (206546120).

Almost surely, 2^1211111211 is an apocalyptic number.

1211111211 is a deficient number, since it is larger than the sum of its proper divisors (441257749).

1211111211 is an equidigital number, since it uses as much as digits as its factorization.

1211111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9388505.

The product of its digits is 4, while the sum is 12.

The square root of 1211111211 is about 34801.0231315115. The cubic root of 1211111211 is about 1065.9283377677.

Adding to 1211111211 its reverse (1121111121), we get a palindrome (2332222332).

The spelling of 1211111211 in words is "one billion, two hundred eleven million, one hundred eleven thousand, two hundred eleven".