1161206221 has 16 divisors (see below), whose sum is σ = 1385975808. Its totient is φ = 951231600.

The previous prime is 1161206177. The next prime is 1161206239. The reversal of 1161206221 is 1226021611.

It is a cyclic number.

It is not a de Polignac number, because 1161206221 - 2⁹ = 1161205709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1161206192 and 1161206201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161206281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250636 + ... + 255226.

It is an arithmetic number, because the mean of its divisors is an integer number (86623488).

Almost surely, 2^1161206221 is an apocalyptic number.

It is an amenable number.

1161206221 is a deficient number, since it is larger than the sum of its proper divisors (224769587).

1161206221 is a wasteful number, since it uses less digits than its factorization.

1161206221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6192.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 1161206221 is about 34076.4760648750. The cubic root of 1161206221 is about 1051.0816430496.

Adding to 1161206221 its reverse (1226021611), we get a palindrome (2387227832).

The spelling of 1161206221 in words is "one billion, one hundred sixty-one million, two hundred six thousand, two hundred twenty-one".