1165577185161 has 27 divisors (see below), whose sum is σ = 1788557594421. Its totient is φ = 731307999744.

The previous prime is 1165577185121. The next prime is 1165577185169. The reversal of 1165577185161 is 1615817755611.

The square root of 1165577185161 is 1079619.

It is a perfect power (a square), and thus also a powerful number.

1165577185161 is a `hidden beast` number, since 1 + 1 + 6 + 5 + 57 + 71 + 8 + 516 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 732950015625 + 432627169536 = 856125^2 + 657744^2 .

It is not a de Polignac number, because 1165577185161 - 2¹⁵ = 1165577152393 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1165577185098 and 1165577185107.

It is not an unprimeable number, because it can be changed into a prime (1165577185169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 55049985 + ... + 55071153.

Almost surely, 2^{1165577185161} is an apocalyptic number.

1165577185161 is the 1079619-th square number.

1165577185161 is the 539810-th centered octagonal number.

It is an amenable number.

1165577185161 is a deficient number, since it is larger than the sum of its proper divisors (622980409260).

1165577185161 is an frugal number, since it uses more digits than its factorization.

1165577185161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42378 (or 21189 counting only the distinct ones).

The product of its digits is 1764000, while the sum is 54.

The spelling of 1165577185161 in words is "one trillion, one hundred sixty-five billion, five hundred seventy-seven million, one hundred eighty-five thousand, one hundred sixty-one".