1216728912 has 40 divisors (see below), whose sum is σ = 3592248256. Its totient is φ = 347636736.

The previous prime is 1216728847. The next prime is 1216728923. The reversal of 1216728912 is 2198276121.

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 7 ways as a sum of consecutive naturals, for example, 1810273 + ... + 1810944.

Almost surely, 2^1216728912 is an apocalyptic number.

1216728912 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1216728912 is an abundant number, since it is smaller than the sum of its proper divisors (2375519344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216728912 is a wasteful number, since it uses less digits than its factorization.

1216728912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3621235 (or 3621229 counting only the distinct ones).

The product of its digits is 24192, while the sum is 39.

The square root of 1216728912 is about 34881.6414751370. The cubic root of 1216728912 is about 1067.5738877204.

The spelling of 1216728912 in words is "one billion, two hundred sixteen million, seven hundred twenty-eight thousand, nine hundred twelve".