1311201121 has 2 divisors, whose sum is σ = 1311201122. Its totient is φ = 1311201120.

The previous prime is 1311201113. The next prime is 1311201127. The reversal of 1311201121 is 1211021131.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1068963025 + 242238096 = 32695^2 + 15564^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311201121 - 2³ = 1311201113 is a prime.

It is a super-3 number, since 3×1311201121³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1311201127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655600560 + 655600561.

It is an arithmetic number, because the mean of its divisors is an integer number (655600561).

Almost surely, 2^1311201121 is an apocalyptic number.

It is an amenable number.

1311201121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311201121 is an equidigital number, since it uses as much as digits as its factorization.

1311201121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1311201121 is about 36210.5111949555. The cubic root of 1311201121 is about 1094.5184933561.

Adding to 1311201121 its reverse (1211021131), we get a palindrome (2522222252).

The spelling of 1311201121 in words is "one billion, three hundred eleven million, two hundred one thousand, one hundred twenty-one".