1638063635616 has 144 divisors (see below), whose sum is σ = 4947163760448. Its totient is φ = 512349235200.

The previous prime is 1638063635569. The next prime is 1638063635617. The reversal of 1638063635616 is 6165363608361.

1638063635616 is a `hidden beast` number, since 16 + 3 + 8 + 0 + 6 + 3 + 6 + 3 + 5 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (1638063635617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1115181 + ... + 2125971.

It is an arithmetic number, because the mean of its divisors is an integer number (34355303892).

Almost surely, 2^{1638063635616} is an apocalyptic number.

1638063635616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638063635616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2473581880224).

1638063635616 is an abundant number, since it is smaller than the sum of its proper divisors (3309100124832).

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

1638063635616 is a wasteful number, since it uses less digits than its factorization.

1638063635616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011155 (or 1011144 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 54.

The spelling of 1638063635616 in words is "one trillion, six hundred thirty-eight billion, sixty-three million, six hundred thirty-five thousand, six hundred sixteen".