2781305 has 4 divisors (see below), whose sum is σ = 3337572. Its totient is φ = 2225040.

The previous prime is 2781301. The next prime is 2781307. The reversal of 2781305 is 5031872.

2781305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 434281 + 2347024 = 659^2 + 1532^2 .

It is not a de Polignac number, because 2781305 - 2² = 2781301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2781301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278126 + ... + 278135.

It is an arithmetic number, because the mean of its divisors is an integer number (834393).

2^2781305 is an apocalyptic number.

It is an amenable number.

2781305 is a deficient number, since it is larger than the sum of its proper divisors (556267).

2781305 is an equidigital number, since it uses as much as digits as its factorization.

2781305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556266.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 2781305 is about 1667.7244976314. The cubic root of 2781305 is about 140.6315852060.

The spelling of 2781305 in words is "two million, seven hundred eighty-one thousand, three hundred five".