1161221611 has 8 divisors (see below), whose sum is σ = 1268362800. Its totient is φ = 1054343040.

The previous prime is 1161221603. The next prime is 1161221623.

It is a happy number.

1161221611 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1161221611 - 2³ = 1161221603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1161221011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56346 + ... + 74143.

It is an arithmetic number, because the mean of its divisors is an integer number (158545350).

Almost surely, 2^1161221611 is an apocalyptic number.

1161221611 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1161221611 is a deficient number, since it is larger than the sum of its proper divisors (107141189).

1161221611 is a wasteful number, since it uses less digits than its factorization.

1161221611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131309.

The product of its digits is 144, while the sum is 22.

The square root of 1161221611 is about 34076.7018797301. The cubic root of 1161221611 is about 1051.0862865186.

The spelling of 1161221611 in words is "one billion, one hundred sixty-one million, two hundred twenty-one thousand, six hundred eleven".