1216655585 has 8 divisors (see below), whose sum is σ = 1460175336. Its totient is φ = 973198720.

The previous prime is 1216655581. The next prime is 1216655593. The reversal of 1216655585 is 5855566121.

It can be written as a sum of positive squares in 4 ways, for example, as 24196561 + 1192459024 = 4919^2 + 34532^2 .

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

It is not a de Polignac number, because 1216655585 - 2² = 1216655581 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216655581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60077 + ... + 77733.

It is an arithmetic number, because the mean of its divisors is an integer number (182521917).

Almost surely, 2^1216655585 is an apocalyptic number.

It is an amenable number.

1216655585 is a deficient number, since it is larger than the sum of its proper divisors (243519751).

1216655585 is a wasteful number, since it uses less digits than its factorization.

1216655585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31443.

The product of its digits is 360000, while the sum is 44.

The square root of 1216655585 is about 34880.5903763110. The cubic root of 1216655585 is about 1067.5524412661.

The spelling of 1216655585 in words is "one billion, two hundred sixteen million, six hundred fifty-five thousand, five hundred eighty-five".