2138644957279 has 4 divisors (see below), whose sum is σ = 2207633504320. Its totient is φ = 2069656410240.

The previous prime is 2138644957261. The next prime is 2138644957301. The reversal of 2138644957279 is 9727594468312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2138644957279 - 2⁷ = 2138644957151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2138644957219) 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, 34494273474 + ... + 34494273535.

It is an arithmetic number, because the mean of its divisors is an integer number (551908376080).

Almost surely, 2^{2138644957279} is an apocalyptic number.

2138644957279 is a deficient number, since it is larger than the sum of its proper divisors (68988547041).

2138644957279 is an equidigital number, since it uses as much as digits as its factorization.

2138644957279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68988547040.

The product of its digits is 182891520, while the sum is 67.

The spelling of 2138644957279 in words is "two trillion, one hundred thirty-eight billion, six hundred forty-four million, nine hundred fifty-seven thousand, two hundred seventy-nine".