2778949 has 4 divisors (see below), whose sum is σ = 2831436. Its totient is φ = 2726464.

The previous prime is 2778917. The next prime is 2778967. The reversal of 2778949 is 9498772.

2778949 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 2122849 + 656100 = 1457^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778949 - 2⁵ = 2778917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2778899 and 2778908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778989) 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, 26164 + ... + 26269.

It is an arithmetic number, because the mean of its divisors is an integer number (707859).

2^2778949 is an apocalyptic number.

It is an amenable number.

2778949 is a deficient number, since it is larger than the sum of its proper divisors (52487).

2778949 is an equidigital number, since it uses as much as digits as its factorization.

2778949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52486.

The product of its digits is 254016, while the sum is 46.

The square root of 2778949 is about 1667.0179963036. The cubic root of 2778949 is about 140.5918650491.

Subtracting from 2778949 its sum of digits (46), we obtain a triangular number (2778903 = T₂₃₅₇).

The spelling of 2778949 in words is "two million, seven hundred seventy-eight thousand, nine hundred forty-nine".