1166215665 has 8 divisors (see below), whose sum is σ = 1865945088. Its totient is φ = 621981680.

The previous prime is 1166215639. The next prime is 1166215681. The reversal of 1166215665 is 5665126611.

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

It is not a de Polignac number, because 1166215665 - 2⁷ = 1166215537 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38873841 + ... + 38873870.

It is an arithmetic number, because the mean of its divisors is an integer number (233243136).

Almost surely, 2^1166215665 is an apocalyptic number.

1166215665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1166215665 is a deficient number, since it is larger than the sum of its proper divisors (699729423).

1166215665 is an equidigital number, since it uses as much as digits as its factorization.

1166215665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77747719.

The product of its digits is 64800, while the sum is 39.

The square root of 1166215665 is about 34149.8999266469. The cubic root of 1166215665 is about 1052.5909302827.

The spelling of 1166215665 in words is "one billion, one hundred sixty-six million, two hundred fifteen thousand, six hundred sixty-five".