2778840 has 128 divisors (see below), whose sum is σ = 9676800. Its totient is φ = 708480.

The previous prime is 2778833. The next prime is 2778851. The reversal of 2778840 is 488772.

2778840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2778795 and 2778804.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 33439 + ... + 33521.

It is an arithmetic number, because the mean of its divisors is an integer number (75600).

2^2778840 is an apocalyptic number.

2778840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2778840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4838400).

2778840 is an abundant number, since it is smaller than the sum of its proper divisors (6897960).

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

2778840 is a wasteful number, since it uses less digits than its factorization.

2778840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 2778840 is about 1666.9853028746. The cubic root of 2778840 is about 140.5900268585.

The spelling of 2778840 in words is "two million, seven hundred seventy-eight thousand, eight hundred forty".