1638682971852 has 12 divisors (see below), whose sum is σ = 3823593601016. Its totient is φ = 546227657280.

The previous prime is 1638682971841. The next prime is 1638682971907. The reversal of 1638682971852 is 2581792868361.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68278457149 + ... + 68278457172.

Almost surely, 2^{1638682971852} is an apocalyptic number.

1638682971852 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1638682971852 is an abundant number, since it is smaller than the sum of its proper divisors (2184910629164).

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

1638682971852 is a wasteful number, since it uses less digits than its factorization.

1638682971852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136556914328 (or 136556914326 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 66.

The spelling of 1638682971852 in words is "one trillion, six hundred thirty-eight billion, six hundred eighty-two million, nine hundred seventy-one thousand, eight hundred fifty-two".