1217643981816 has 32 divisors (see below), whose sum is σ = 3044952714960. Its totient is φ = 405768959232.

The previous prime is 1217643981769. The next prime is 1217643981839. The reversal of 1217643981816 is 6181893467121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6934485 + ... + 7107908.

Almost surely, 2^{1217643981816} is an apocalyptic number.

It is an amenable number.

1217643981816 is an abundant number, since it is smaller than the sum of its proper divisors (1827308733144).

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

1217643981816 is a wasteful number, since it uses less digits than its factorization.

1217643981816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14046015 (or 14046011 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 57.

The spelling of 1217643981816 in words is "one trillion, two hundred seventeen billion, six hundred forty-three million, nine hundred eighty-one thousand, eight hundred sixteen".