1216242866 has 16 divisors (see below), whose sum is σ = 1933792056. Its totient is φ = 571723776.

The previous prime is 1216242857. The next prime is 1216242889. The reversal of 1216242866 is 6682426121.

It can be written as a sum of positive squares in 4 ways, for example, as 570015625 + 646227241 = 23875^2 + 25421^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12770 + ... + 50946.

Almost surely, 2^1216242866 is an apocalyptic number.

1216242866 is a deficient number, since it is larger than the sum of its proper divisors (717549190).

1216242866 is a wasteful number, since it uses less digits than its factorization.

1216242866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39133.

The product of its digits is 55296, while the sum is 38.

The square root of 1216242866 is about 34874.6737045668. The cubic root of 1216242866 is about 1067.4317144114.

Adding to 1216242866 its reverse (6682426121), we get a palindrome (7898668987).

The spelling of 1216242866 in words is "one billion, two hundred sixteen million, two hundred forty-two thousand, eight hundred sixty-six".