1216911812 has 24 divisors (see below), whose sum is σ = 2141892480. Its totient is φ = 604954080.

The previous prime is 1216911811. The next prime is 1216911823. The reversal of 1216911812 is 2181196121.

It is not an unprimeable number, because it can be changed into a prime (1216911811) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 569987 + ... + 572117.

It is an arithmetic number, because the mean of its divisors is an integer number (89245520).

Almost surely, 2^1216911812 is an apocalyptic number.

It is an amenable number.

1216911812 is a deficient number, since it is larger than the sum of its proper divisors (924980668).

1216911812 is a wasteful number, since it uses less digits than its factorization.

1216911812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2891 (or 2889 counting only the distinct ones).

The product of its digits is 1728, while the sum is 32.

The square root of 1216911812 is about 34884.2630995697. The cubic root of 1216911812 is about 1067.6273779923.

The spelling of 1216911812 in words is "one billion, two hundred sixteen million, nine hundred eleven thousand, eight hundred twelve".