2778438 has 32 divisors (see below), whose sum is σ = 6048000. Its totient is φ = 845856.

The previous prime is 2778421. The next prime is 2778439. The reversal of 2778438 is 8348772.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an Ulam number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2778396 and 2778405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13863 + ... + 14061.

It is an arithmetic number, because the mean of its divisors is an integer number (189000).

2^2778438 is an apocalyptic number.

2778438 is an abundant number, since it is smaller than the sum of its proper divisors (3269562).

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

2778438 is a wasteful number, since it uses less digits than its factorization.

2778438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396.

The product of its digits is 75264, while the sum is 39.

The square root of 2778438 is about 1666.8647215656. The cubic root of 2778438 is about 140.5832470612.

The spelling of 2778438 in words is "two million, seven hundred seventy-eight thousand, four hundred thirty-eight".