2778786 has 40 divisors (see below), whose sum is σ = 6599340. Its totient is φ = 870912.

The previous prime is 2778779. The next prime is 2778793. The reversal of 2778786 is 6878772.

2778786 is nontrivially palindromic in base 16.

It is an interprime number because it is at equal distance from previous prime (2778779) and next prime (2778793).

It can be written as a sum of positive squares in 2 ways, for example, as 2772225 + 6561 = 1665^2 + 81^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2250 + ... + 3258.

2^2778786 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2778786, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3299670).

2778786 is an abundant number, since it is smaller than the sum of its proper divisors (3820554).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2778786 is a wasteful number, since it uses less digits than its factorization.

2778786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040 (or 1031 counting only the distinct ones).

The product of its digits is 263424, while the sum is 45.

The square root of 2778786 is about 1666.9691058925. The cubic root of 2778786 is about 140.5891161775.

The spelling of 2778786 in words is "two million, seven hundred seventy-eight thousand, seven hundred eighty-six".