1216440165 has 16 divisors (see below), whose sum is σ = 1946737728. Its totient is φ = 648623616.

The previous prime is 1216440143. The next prime is 1216440221. The reversal of 1216440165 is 5610446121.

It is not a de Polignac number, because 1216440165 - 2⁵ = 1216440133 is a prime.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 120597 + ... + 130293.

It is an arithmetic number, because the mean of its divisors is an integer number (121671108).

Almost surely, 2^1216440165 is an apocalyptic number.

1216440165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216440165 is a deficient number, since it is larger than the sum of its proper divisors (730297563).

1216440165 is an equidigital number, since it uses as much as digits as its factorization.

1216440165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18068.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 1216440165 is about 34877.5022758224. The cubic root of 1216440165 is about 1067.4894309056.

Adding to 1216440165 its reverse (5610446121), we get a palindrome (6826886286).

The spelling of 1216440165 in words is "one billion, two hundred sixteen million, four hundred forty thousand, one hundred sixty-five".