1216323585 has 24 divisors (see below), whose sum is σ = 2157327744. Its totient is φ = 633618720.

The previous prime is 1216323571. The next prime is 1216323587. The reversal of 1216323585 is 5853236121.

1216323585 is a `hidden beast` number, since 12 + 1 + 63 + 2 + 3 + 585 = 666.

It is not a de Polignac number, because 1216323585 - 2⁴ = 1216323569 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1216323587) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 312361 + ... + 316230.

It is an arithmetic number, because the mean of its divisors is an integer number (89888656).

Almost surely, 2^1216323585 is an apocalyptic number.

1216323585 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216323585 is a deficient number, since it is larger than the sum of its proper divisors (941004159).

1216323585 is a wasteful number, since it uses less digits than its factorization.

1216323585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628645 (or 628642 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 1216323585 is about 34875.8309578424. The cubic root of 1216323585 is about 1067.4553281476.

The spelling of 1216323585 in words is "one billion, two hundred sixteen million, three hundred twenty-three thousand, five hundred eighty-five".