2778205 has 8 divisors (see below), whose sum is σ = 3343032. Its totient is φ = 2216448.

The previous prime is 2778203. The next prime is 2778227. The reversal of 2778205 is 5028772.

2778205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 29241 + 2748964 = 171^2 + 1658^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2778205 - 2¹ = 2778203 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778203) 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 7 ways as a sum of consecutive naturals, for example, 2497 + ... + 3433.

It is an arithmetic number, because the mean of its divisors is an integer number (417879).

2^2778205 is an apocalyptic number.

It is an amenable number.

2778205 is a deficient number, since it is larger than the sum of its proper divisors (564827).

2778205 is an equidigital number, since it uses as much as digits as its factorization.

2778205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 2778205 is about 1666.7948284057. The cubic root of 2778205 is about 140.5793171777.

The spelling of 2778205 in words is "two million, seven hundred seventy-eight thousand, two hundred five".