2778493 has 4 divisors (see below), whose sum is σ = 2784348. Its totient is φ = 2772640.

The previous prime is 2778481. The next prime is 2778521. The reversal of 2778493 is 3948772.

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 2067844 + 710649 = 1438^2 + 843^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778493 - 2⁹ = 2777981 is a prime.

It is a Duffinian number.

2778493 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2146 + ... + 3187.

It is an arithmetic number, because the mean of its divisors is an integer number (696087).

2^2778493 is an apocalyptic number.

It is an amenable number.

2778493 is a deficient number, since it is larger than the sum of its proper divisors (5855).

2778493 is an equidigital number, since it uses as much as digits as its factorization.

2778493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5854.

The product of its digits is 84672, while the sum is 40.

The square root of 2778493 is about 1666.8812195235. The cubic root of 2778493 is about 140.5841746840.

The spelling of 2778493 in words is "two million, seven hundred seventy-eight thousand, four hundred ninety-three".