2644639 has 6 divisors (see below), whose sum is σ = 2809664. Its totient is φ = 2488800.

The previous prime is 2644637. The next prime is 2644657. The reversal of 2644639 is 9364462.

It is not a de Polignac number, because 2644639 - 2¹ = 2644637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2644637) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4287 + ... + 4864.

2^2644639 is an apocalyptic number.

2644639 is a deficient number, since it is larger than the sum of its proper divisors (165025).

2644639 is an equidigital number, since it uses as much as digits as its factorization.

2644639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9185 (or 9168 counting only the distinct ones).

The product of its digits is 31104, while the sum is 34.

The square root of 2644639 is about 1626.2346079210. The cubic root of 2644639 is about 138.2893703946.

The spelling of 2644639 in words is "two million, six hundred forty-four thousand, six hundred thirty-nine".