1211442161 has 2 divisors, whose sum is σ = 1211442162. Its totient is φ = 1211442160.

The previous prime is 1211442097. The next prime is 1211442173. The reversal of 1211442161 is 1612441121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1207215025 + 4227136 = 34745^2 + 2056^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211442161 - 2⁶ = 1211442097 is a prime.

It is a super-3 number, since 3×1211442161³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1211442191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605721080 + 605721081.

It is an arithmetic number, because the mean of its divisors is an integer number (605721081).

Almost surely, 2^1211442161 is an apocalyptic number.

It is an amenable number.

1211442161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211442161 is an equidigital number, since it uses as much as digits as its factorization.

1211442161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 23.

The square root of 1211442161 is about 34805.7776956643. Note that the first 3 decimals coincide. The cubic root of 1211442161 is about 1066.0254212979.

Adding to 1211442161 its reverse (1612441121), we get a palindrome (2823883282).

The spelling of 1211442161 in words is "one billion, two hundred eleven million, four hundred forty-two thousand, one hundred sixty-one".