1211321081 has 2 divisors, whose sum is σ = 1211321082. Its totient is φ = 1211321080.

The previous prime is 1211321021. The next prime is 1211321093. The reversal of 1211321081 is 1801231121.

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., 686178025 + 525143056 = 26195^2 + 22916^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211321081 - 2⁶ = 1211321017 is a prime.

It is a super-2 number, since 2×1211321081² = 2934597522550017122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1211321021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605660540 + 605660541.

It is an arithmetic number, because the mean of its divisors is an integer number (605660541).

Almost surely, 2^1211321081 is an apocalyptic number.

It is an amenable number.

1211321081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211321081 is an equidigital number, since it uses as much as digits as its factorization.

1211321081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 20.

The square root of 1211321081 is about 34804.0382858082. The cubic root of 1211321081 is about 1065.9899047699.

The spelling of 1211321081 in words is "one billion, two hundred eleven million, three hundred twenty-one thousand, eighty-one".