2138427672565 has 4 divisors (see below), whose sum is σ = 2566113207084. Its totient is φ = 1710742138048.

The previous prime is 2138427672559. The next prime is 2138427672617. The reversal of 2138427672565 is 5652767248312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 879350681169 + 1259076991396 = 937737^2 + 1122086^2 .

It is a cyclic number.

It is not a de Polignac number, because 2138427672565 - 2⁹ = 2138427672053 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213842767252 + ... + 213842767261.

It is an arithmetic number, because the mean of its divisors is an integer number (641528301771).

Almost surely, 2^{2138427672565} is an apocalyptic number.

It is an amenable number.

2138427672565 is a deficient number, since it is larger than the sum of its proper divisors (427685534519).

2138427672565 is an equidigital number, since it uses as much as digits as its factorization.

2138427672565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427685534518.

The product of its digits is 33868800, while the sum is 58.

The spelling of 2138427672565 in words is "two trillion, one hundred thirty-eight billion, four hundred twenty-seven million, six hundred seventy-two thousand, five hundred sixty-five".