1166558161 has 4 divisors (see below), whose sum is σ = 1181324800. Its totient is φ = 1151791524.

The previous prime is 1166558153. The next prime is 1166558227. The reversal of 1166558161 is 1618556611.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1618556611 = 7 ⋅231222373.

It is a cyclic number.

It is not a de Polignac number, because 1166558161 - 2³ = 1166558153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1166558131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7383201 + ... + 7383358.

It is an arithmetic number, because the mean of its divisors is an integer number (295331200).

Almost surely, 2^1166558161 is an apocalyptic number.

It is an amenable number.

1166558161 is a deficient number, since it is larger than the sum of its proper divisors (14766639).

1166558161 is an equidigital number, since it uses as much as digits as its factorization.

1166558161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14766638.

The product of its digits is 43200, while the sum is 40.

The square root of 1166558161 is about 34154.9141559454. The cubic root of 1166558161 is about 1052.6939623686.

The spelling of 1166558161 in words is "one billion, one hundred sixty-six million, five hundred fifty-eight thousand, one hundred sixty-one".