2780638 has 32 divisors (see below), whose sum is σ = 5068800. Its totient is φ = 1118880.

The previous prime is 2780623. The next prime is 2780641. The reversal of 2780638 is 8360872.

It is a happy number.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18588 + ... + 18736.

It is an arithmetic number, because the mean of its divisors is an integer number (158400).

2^2780638 is an apocalyptic number.

2780638 is a deficient number, since it is larger than the sum of its proper divisors (2288162).

2780638 is a wasteful number, since it uses less digits than its factorization.

2780638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 2780638 is about 1667.5245125635. The cubic root of 2780638 is about 140.6203424301.

The spelling of 2780638 in words is "two million, seven hundred eighty thousand, six hundred thirty-eight".