1211561861149 has 2 divisors, whose sum is σ = 1211561861150. Its totient is φ = 1211561861148.

The previous prime is 1211561861143. The next prime is 1211561861183. The reversal of 1211561861149 is 9411681651121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 742087488025 + 469474373124 = 861445^2 + 685182^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211561861149 - 2²⁵ = 1211528306717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211561861099 and 1211561861108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211561861143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605780930574 + 605780930575.

It is an arithmetic number, because the mean of its divisors is an integer number (605780930575).

Almost surely, 2^{1211561861149} is an apocalyptic number.

It is an amenable number.

1211561861149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211561861149 is an equidigital number, since it uses as much as digits as its factorization.

1211561861149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 46.

The spelling of 1211561861149 in words is "one trillion, two hundred eleven billion, five hundred sixty-one million, eight hundred sixty-one thousand, one hundred forty-nine".