1216776912 has 160 divisors (see below), whose sum is σ = 3562272000. Its totient is φ = 355086336.

The previous prime is 1216776893. The next prime is 1216776923. The reversal of 1216776912 is 2196776121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2138164 + ... + 2138732.

It is an arithmetic number, because the mean of its divisors is an integer number (22264200).

Almost surely, 2^1216776912 is an apocalyptic number.

1216776912 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216776912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1781136000).

1216776912 is an abundant number, since it is smaller than the sum of its proper divisors (2345495088).

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

1216776912 is a wasteful number, since it uses less digits than its factorization.

1216776912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765 (or 759 counting only the distinct ones).

The product of its digits is 63504, while the sum is 42.

The square root of 1216776912 is about 34882.3295093662. The cubic root of 1216776912 is about 1067.5879261455.

It can be divided in two parts, 1216 and 776912, that added together give a triangular number (778128 = T₁₂₄₇).

The spelling of 1216776912 in words is "one billion, two hundred sixteen million, seven hundred seventy-six thousand, nine hundred twelve".