1211343121 has 2 divisors, whose sum is σ = 1211343122. Its totient is φ = 1211343120.

The previous prime is 1211343113. The next prime is 1211343127. The reversal of 1211343121 is 1213431121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 796650625 + 414692496 = 28225^2 + 20364^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211343121 - 2³ = 1211343113 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211343127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605671560 + 605671561.

It is an arithmetic number, because the mean of its divisors is an integer number (605671561).

Almost surely, 2^1211343121 is an apocalyptic number.

It is an amenable number.

1211343121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211343121 is an equidigital number, since it uses as much as digits as its factorization.

1211343121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 19.

The square root of 1211343121 is about 34804.3549142920. The cubic root of 1211343121 is about 1065.9963699632.

Adding to 1211343121 its reverse (1213431121), we get a palindrome (2424774242).

The spelling of 1211343121 in words is "one billion, two hundred eleven million, three hundred forty-three thousand, one hundred twenty-one".