1216555012 has 12 divisors (see below), whose sum is σ = 2129286096. Its totient is φ = 608187560.

The previous prime is 1216554961. The next prime is 1216555069. The reversal of 1216555012 is 2105556121.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14823 + ... + 51505.

It is an arithmetic number, because the mean of its divisors is an integer number (177440508).

Almost surely, 2^1216555012 is an apocalyptic number.

It is an amenable number.

1216555012 is a deficient number, since it is larger than the sum of its proper divisors (912731084).

1216555012 is a wasteful number, since it uses less digits than its factorization.

1216555012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44978 (or 44976 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 28.

The square root of 1216555012 is about 34879.1486708033. The cubic root of 1216555012 is about 1067.5230245844.

The spelling of 1216555012 in words is "one billion, two hundred sixteen million, five hundred fifty-five thousand, twelve".