1216638756412 has 12 divisors (see below), whose sum is σ = 2138255670096. Its totient is φ = 605708564960.

The previous prime is 1216638756397. The next prime is 1216638756433. The reversal of 1216638756412 is 2146578366121.

It is a super-2 number, since 2×1216638756412² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1216638756412.

It is a congruent number.

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, 652702264 + ... + 652704127.

It is an arithmetic number, because the mean of its divisors is an integer number (178187972508).

Almost surely, 2^{1216638756412} is an apocalyptic number.

It is an amenable number.

1216638756412 is a deficient number, since it is larger than the sum of its proper divisors (921616913684).

1216638756412 is a wasteful number, since it uses less digits than its factorization.

1216638756412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305406628 (or 1305406626 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 52.

The spelling of 1216638756412 in words is "one trillion, two hundred sixteen billion, six hundred thirty-eight million, seven hundred fifty-six thousand, four hundred twelve".