1182191981 has 2 divisors, whose sum is σ = 1182191982. Its totient is φ = 1182191980.

The previous prime is 1182191953. The next prime is 1182191999. The reversal of 1182191981 is 1891912811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1039030756 + 143161225 = 32234^2 + 11965^2 .

It is a cyclic number.

It is not a de Polignac number, because 1182191981 - 2¹⁰ = 1182190957 is a prime.

It is a super-2 number, since 2×1182191981² = 2795155759881408722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1182191911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 591095990 + 591095991.

It is an arithmetic number, because the mean of its divisors is an integer number (591095991).

Almost surely, 2^1182191981 is an apocalyptic number.

It is an amenable number.

1182191981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1182191981 is an equidigital number, since it uses as much as digits as its factorization.

1182191981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 41.

The square root of 1182191981 is about 34383.0187883496. The cubic root of 1182191981 is about 1057.3757265377.

The spelling of 1182191981 in words is "one billion, one hundred eighty-two million, one hundred ninety-one thousand, nine hundred eighty-one".