2138644495872 has 120 divisors (see below), whose sum is σ = 6189470567280. Its totient is φ = 710895206400.

The previous prime is 2138644495861. The next prime is 2138644495903. The reversal of 2138644495872 is 2785944468312.

2138644495872 is a `hidden beast` number, since 2 + 1 + 3 + 8 + 6 + 4 + 4 + 49 + 587 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1007872 + ... + 2300672.

It is an arithmetic number, because the mean of its divisors is an integer number (51578921394).

Almost surely, 2^{2138644495872} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2138644495872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3094735283640).

2138644495872 is an abundant number, since it is smaller than the sum of its proper divisors (4050826071408).

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

2138644495872 is a wasteful number, since it uses less digits than its factorization.

2138644495872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293184 (or 1293165 counting only the distinct ones).

The product of its digits is 92897280, while the sum is 63.

The spelling of 2138644495872 in words is "two trillion, one hundred thirty-eight billion, six hundred forty-four million, four hundred ninety-five thousand, eight hundred seventy-two".