1216231216 has 20 divisors (see below), whose sum is σ = 2413923624. Its totient is φ = 593283200.

The previous prime is 1216231213. The next prime is 1216231231. The reversal of 1216231216 is 6121326121.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1216231213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 926350 + ... + 927661.

Almost surely, 2^1216231216 is an apocalyptic number.

1216231216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1216231216 is a deficient number, since it is larger than the sum of its proper divisors (1197692408).

1216231216 is a wasteful number, since it uses less digits than its factorization.

1216231216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854060 (or 1854054 counting only the distinct ones).

The product of its digits is 864, while the sum is 25.

The square root of 1216231216 is about 34874.5066775145. The cubic root of 1216231216 is about 1067.4283062053.

Adding to 1216231216 its reverse (6121326121), we get a palindrome (7337557337).

The spelling of 1216231216 in words is "one billion, two hundred sixteen million, two hundred thirty-one thousand, two hundred sixteen".