2778149 has 4 divisors (see below), whose sum is σ = 3030720. Its totient is φ = 2525580.

The previous prime is 2778143. The next prime is 2778151. The reversal of 2778149 is 9418772.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2778149 - 2¹⁶ = 2712613 is a prime.

It is a super-2 number, since 2×2778149² = 15436223732402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126269 + ... + 126290.

It is an arithmetic number, because the mean of its divisors is an integer number (757680).

2^2778149 is an apocalyptic number.

It is an amenable number.

2778149 is a deficient number, since it is larger than the sum of its proper divisors (252571).

2778149 is a wasteful number, since it uses less digits than its factorization.

2778149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252570.

The product of its digits is 28224, while the sum is 38.

The square root of 2778149 is about 1666.7780296128. The cubic root of 2778149 is about 140.5783726237.

The spelling of 2778149 in words is "two million, seven hundred seventy-eight thousand, one hundred forty-nine".