2640638 has 32 divisors (see below), whose sum is σ = 5322240. Its totient is φ = 948960.

The previous prime is 2640581. The next prime is 2640643. The reversal of 2640638 is 8360462.

2640638 is digitally balanced in base 8, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

2640638 is strictly pandigital in base 8.

It is a self number, because there is not a number n which added to its sum of digits gives 2640638.

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, 1343 + ... + 2661.

It is an arithmetic number, because the mean of its divisors is an integer number (166320).

2^2640638 is an apocalyptic number.

2640638 is an abundant number, since it is smaller than the sum of its proper divisors (2681602).

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

2640638 is a wasteful number, since it uses less digits than its factorization.

2640638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 2640638 is about 1625.0039999951. The cubic root of 2640638 is about 138.2195971631.

The spelling of 2640638 in words is "two million, six hundred forty thousand, six hundred thirty-eight".