1638555506912 has 24 divisors (see below), whose sum is σ = 3235652115192. Its totient is φ = 816802588800.

The previous prime is 1638555506911. The next prime is 1638555506933. The reversal of 1638555506912 is 2196055558361.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638555506911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77338139 + ... + 77359322.

It is an arithmetic number, because the mean of its divisors is an integer number (134818838133).

Almost surely, 2^{1638555506912} is an apocalyptic number.

It is an amenable number.

1638555506912 is a deficient number, since it is larger than the sum of its proper divisors (1597096608280).

1638555506912 is a wasteful number, since it uses less digits than its factorization.

1638555506912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154697802 (or 154697794 counting only the distinct ones).

The product of its (nonzero) digits is 9720000, while the sum is 56.

The spelling of 1638555506912 in words is "one trillion, six hundred thirty-eight billion, five hundred fifty-five million, five hundred six thousand, nine hundred twelve".