1166221161 has 24 divisors (see below), whose sum is σ = 1931791680. Its totient is φ = 664127136.

The previous prime is 1166221151. The next prime is 1166221183. The reversal of 1166221161 is 1611226611.

It is not a de Polignac number, because 1166221161 - 2⁷ = 1166221033 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1166221151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13131 + ... + 50048.

It is an arithmetic number, because the mean of its divisors is an integer number (80491320).

Almost surely, 2^1166221161 is an apocalyptic number.

It is an amenable number.

1166221161 is a deficient number, since it is larger than the sum of its proper divisors (765570519).

1166221161 is a wasteful number, since it uses less digits than its factorization.

1166221161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63485 (or 63482 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 1166221161 is about 34149.9803953092. The cubic root of 1166221161 is about 1052.5925837878.

Adding to 1166221161 its reverse (1611226611), we get a palindrome (2777447772).

It can be divided in two parts, 11662 and 21161, that added together give a palindrome (32823).

The spelling of 1166221161 in words is "one billion, one hundred sixty-six million, two hundred twenty-one thousand, one hundred sixty-one".