1216433565 has 32 divisors (see below), whose sum is σ = 2237126400. Its totient is φ = 626391360.

The previous prime is 1216433563. The next prime is 1216433639. The reversal of 1216433565 is 5653346121.

1216433565 is a `hidden beast` number, since 1 + 2 + 1 + 64 + 33 + 565 = 666.

It is not a de Polignac number, because 1216433565 - 2¹ = 1216433563 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216433563) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 151441 + ... + 159270.

It is an arithmetic number, because the mean of its divisors is an integer number (69910200).

Almost surely, 2^1216433565 is an apocalyptic number.

1216433565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216433565 is a deficient number, since it is larger than the sum of its proper divisors (1020692835).

1216433565 is a wasteful number, since it uses less digits than its factorization.

1216433565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310754 (or 310748 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 1216433565 is about 34877.4076588269. The cubic root of 1216433565 is about 1067.4875002878.

Adding to 1216433565 its reverse (5653346121), we get a palindrome (6869779686).

The spelling of 1216433565 in words is "one billion, two hundred sixteen million, four hundred thirty-three thousand, five hundred sixty-five".