1638925568128 has 32 divisors (see below), whose sum is σ = 3340978367760. Its totient is φ = 800405507328.

The previous prime is 1638925568117. The next prime is 1638925568129. The reversal of 1638925568128 is 8218655298361.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a self number, because there is not a number n which added to its sum of digits gives 1638925568128.

It is not an unprimeable number, because it can be changed into a prime (1638925568129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148879450 + ... + 148890457.

Almost surely, 2^{1638925568128} is an apocalyptic number.

It is an amenable number.

1638925568128 is an abundant number, since it is smaller than the sum of its proper divisors (1702052799632).

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

1638925568128 is an equidigital number, since it uses as much as digits as its factorization.

1638925568128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297769964 (or 297769952 counting only the distinct ones).

The product of its digits is 49766400, while the sum is 64.

The spelling of 1638925568128 in words is "one trillion, six hundred thirty-eight billion, nine hundred twenty-five million, five hundred sixty-eight thousand, one hundred twenty-eight".