2138593865 has 4 divisors (see below), whose sum is σ = 2566312644. Its totient is φ = 1710875088.

The previous prime is 2138593819. The next prime is 2138593867. The reversal of 2138593865 is 5683958312.

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 624450121 + 1514143744 = 24989^2 + 38912^2 .

It is a cyclic number.

It is not a de Polignac number, because 2138593865 - 2⁸ = 2138593609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2138593867) 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, 213859382 + ... + 213859391.

It is an arithmetic number, because the mean of its divisors is an integer number (641578161).

Almost surely, 2^2138593865 is an apocalyptic number.

It is an amenable number.

2138593865 is a deficient number, since it is larger than the sum of its proper divisors (427718779).

2138593865 is an equidigital number, since it uses as much as digits as its factorization.

2138593865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427718778.

The product of its digits is 1555200, while the sum is 50.

The square root of 2138593865 is about 46244.9333981573. The cubic root of 2138593865 is about 1288.3764333234.

The spelling of 2138593865 in words is "two billion, one hundred thirty-eight million, five hundred ninety-three thousand, eight hundred sixty-five".