1211511241 has 2 divisors, whose sum is σ = 1211511242. Its totient is φ = 1211511240.

The previous prime is 1211511209. The next prime is 1211511253. The reversal of 1211511241 is 1421151121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 771728400 + 439782841 = 27780^2 + 20971^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211511241 - 2⁵ = 1211511209 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221511241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605755620 + 605755621.

It is an arithmetic number, because the mean of its divisors is an integer number (605755621).

Almost surely, 2^1211511241 is an apocalyptic number.

It is an amenable number.

1211511241 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211511241 is an equidigital number, since it uses as much as digits as its factorization.

1211511241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 80, while the sum is 19.

The square root of 1211511241 is about 34806.7700454955. The cubic root of 1211511241 is about 1066.0456835492.

Adding to 1211511241 its reverse (1421151121), we get a palindrome (2632662362).

The spelling of 1211511241 in words is "one billion, two hundred eleven million, five hundred eleven thousand, two hundred forty-one".