1165551161 has 12 divisors (see below), whose sum is σ = 1245118320. Its totient is φ = 1090812480.

The previous prime is 1165551103. The next prime is 1165551173. The reversal of 1165551161 is 1611555611.

It is not a de Polignac number, because 1165551161 - 2¹⁰ = 1165550137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1165511161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40466 + ... + 62996.

It is an arithmetic number, because the mean of its divisors is an integer number (103759860).

Almost surely, 2^1165551161 is an apocalyptic number.

It is an amenable number.

1165551161 is a deficient number, since it is larger than the sum of its proper divisors (79567159).

1165551161 is a wasteful number, since it uses less digits than its factorization.

1165551161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22744 (or 22727 counting only the distinct ones).

The product of its digits is 4500, while the sum is 32.

The square root of 1165551161 is about 34140.1693170962. The cubic root of 1165551161 is about 1052.3909719061.

The spelling of 1165551161 in words is "one billion, one hundred sixty-five million, five hundred fifty-one thousand, one hundred sixty-one".