2778623 has 4 divisors (see below), whose sum is σ = 2868288. Its totient is φ = 2688960.

The previous prime is 2778619. The next prime is 2778647. The reversal of 2778623 is 3268772.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2778623 - 2² = 2778619 is a prime.

It is a super-2 number, since 2×2778623² = 15441491552258, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2¹⁷ + 7³ + 7⁵ + 8³ + 6⁴ + 2²¹ + 3¹² .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778673) 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, 44786 + ... + 44847.

It is an arithmetic number, because the mean of its divisors is an integer number (717072).

2^2778623 is an apocalyptic number.

2778623 is a deficient number, since it is larger than the sum of its proper divisors (89665).

2778623 is an equidigital number, since it uses as much as digits as its factorization.

2778623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89664.

The product of its digits is 28224, while the sum is 35.

The square root of 2778623 is about 1666.9202140475. The cubic root of 2778623 is about 140.5863671984.

The spelling of 2778623 in words is "two million, seven hundred seventy-eight thousand, six hundred twenty-three".