2638656 has 70 divisors (see below), whose sum is σ = 7837170. Its totient is φ = 877824.

The previous prime is 2638651. The next prime is 2638667. The reversal of 2638656 is 6568362.

It can be written as a sum of positive squares in only one way, i.e., 2509056 + 129600 = 1584^2 + 360^2 .

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

It is a d-powerful number, because it can be written as 2¹⁹ + 6⁴ + 3⁵ + 8⁷ + 6⁵ + 5³ + 6⁵ .

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 2638656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638651) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4930 + ... + 5438.

2^2638656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2638656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3918585).

2638656 is an abundant number, since it is smaller than the sum of its proper divisors (5198514).

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

2638656 is an equidigital number, since it uses as much as digits as its factorization.

2638656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533 (or 514 counting only the distinct ones).

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

The square root of 2638656 is about 1624.3940408657. The cubic root of 2638656 is about 138.1850070615.

The spelling of 2638656 in words is "two million, six hundred thirty-eight thousand, six hundred fifty-six".