2656638 has 60 divisors (see below), whose sum is σ = 6423648. Its totient is φ = 819720.

The previous prime is 2656627. The next prime is 2656639. The reversal of 2656638 is 8366562.

2656638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656639) by changing a digit.

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 29 ways as a sum of consecutive naturals, for example, 85683 + ... + 85713.

2^2656638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2656638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3211824).

2656638 is an abundant number, since it is smaller than the sum of its proper divisors (3767010).

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

2656638 is a wasteful number, since it uses less digits than its factorization.

2656638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 59 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 2656638 is about 1629.9196299204. The cubic root of 2656638 is about 138.4981992667.

It can be divided in two parts, 265 and 6638, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 2656638 in words is "two million, six hundred fifty-six thousand, six hundred thirty-eight".