2781738065 has 4 divisors (see below), whose sum is σ = 3338085684. Its totient is φ = 2225390448.

The previous prime is 2781738053. The next prime is 2781738119. The reversal of 2781738065 is 5608371872.

It is a happy number.

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 1620223504 + 1161514561 = 40252^2 + 34081^2 .

It is a cyclic number.

It is not a de Polignac number, because 2781738065 - 2¹⁴ = 2781721681 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278173802 + ... + 278173811.

It is an arithmetic number, because the mean of its divisors is an integer number (834521421).

Almost surely, 2^2781738065 is an apocalyptic number.

It is an amenable number.

2781738065 is a deficient number, since it is larger than the sum of its proper divisors (556347619).

2781738065 is an equidigital number, since it uses as much as digits as its factorization.

2781738065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556347618.

The product of its (nonzero) digits is 564480, while the sum is 47.

The square root of 2781738065 is about 52742.1848713153. The cubic root of 2781738065 is about 1406.3888387299.

The spelling of 2781738065 in words is "two billion, seven hundred eighty-one million, seven hundred thirty-eight thousand, sixty-five".