1166991409 has 2 divisors, whose sum is σ = 1166991410. Its totient is φ = 1166991408.

The previous prime is 1166991379. The next prime is 1166991481. The reversal of 1166991409 is 9041996611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1015824384 + 151167025 = 31872^2 + 12295^2 .

It is an emirp because it is prime and its reverse (9041996611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1166991409 - 2⁵ = 1166991377 is a prime.

It is not a weakly prime, because it can be changed into another prime (1166991499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583495704 + 583495705.

It is an arithmetic number, because the mean of its divisors is an integer number (583495705).

Almost surely, 2^1166991409 is an apocalyptic number.

It is an amenable number.

1166991409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1166991409 is an equidigital number, since it uses as much as digits as its factorization.

1166991409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 1166991409 is about 34161.2559634449. The cubic root of 1166991409 is about 1052.8242662316.

The spelling of 1166991409 in words is "one billion, one hundred sixty-six million, nine hundred ninety-one thousand, four hundred nine".