1165561165 has 8 divisors (see below), whose sum is σ = 1411745760. Its totient is φ = 923734032.

The previous prime is 1165561153. The next prime is 1165561183. The reversal of 1165561165 is 5611655611.

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 1165561165 - 2²¹ = 1163464013 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1088775 + ... + 1089844.

It is an arithmetic number, because the mean of its divisors is an integer number (176468220).

Almost surely, 2^1165561165 is an apocalyptic number.

It is an amenable number.

1165561165 is a deficient number, since it is larger than the sum of its proper divisors (246184595).

1165561165 is a wasteful number, since it uses less digits than its factorization.

1165561165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2178731.

The product of its digits is 27000, while the sum is 37.

The square root of 1165561165 is about 34140.3158304079. The cubic root of 1165561165 is about 1052.3939828105.

It can be divided in two parts, 1165 and 561165, that added together give a triangular number (562330 = T₁₀₆₀).

The spelling of 1165561165 in words is "one billion, one hundred sixty-five million, five hundred sixty-one thousand, one hundred sixty-five".