2781905 has 16 divisors (see below), whose sum is σ = 3880704. Its totient is φ = 1874880.

The previous prime is 2781901. The next prime is 2781913. The reversal of 2781905 is 5091872.

2781905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2781905 - 2² = 2781901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2781901) 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 15 ways as a sum of consecutive naturals, for example, 1484 + ... + 2786.

It is an arithmetic number, because the mean of its divisors is an integer number (242544).

2^2781905 is an apocalyptic number.

It is an amenable number.

2781905 is a deficient number, since it is larger than the sum of its proper divisors (1098799).

2781905 is a wasteful number, since it uses less digits than its factorization.

2781905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1376.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 2781905 is about 1667.9043737577. The cubic root of 2781905 is about 140.6416971120.

The spelling of 2781905 in words is "two million, seven hundred eighty-one thousand, nine hundred five".