1216442005 has 4 divisors (see below), whose sum is σ = 1459730412. Its totient is φ = 973153600.

The previous prime is 1216441981. The next prime is 1216442011. The reversal of 1216442005 is 5002446121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5002446121 = 41 ⋅122010881.

It can be written as a sum of positive squares in 2 ways, for example, as 661415524 + 555026481 = 25718^2 + 23559^2 .

It is not a de Polignac number, because 1216442005 - 2⁹ = 1216441493 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 121644196 + ... + 121644205.

It is an arithmetic number, because the mean of its divisors is an integer number (364932603).

Almost surely, 2^1216442005 is an apocalyptic number.

It is an amenable number.

1216442005 is a deficient number, since it is larger than the sum of its proper divisors (243288407).

1216442005 is an equidigital number, since it uses as much as digits as its factorization.

1216442005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243288406.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 1216442005 is about 34877.5286538482. The cubic root of 1216442005 is about 1067.4899691372.

Adding to 1216442005 its reverse (5002446121), we get a palindrome (6218888126).

The spelling of 1216442005 in words is "one billion, two hundred sixteen million, four hundred forty-two thousand, five".