2638645 has 4 divisors (see below), whose sum is σ = 3166380. Its totient is φ = 2110912.

The previous prime is 2638633. The next prime is 2638651. The reversal of 2638645 is 5468362.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5468362 = 2 ⋅2734181.

It can be written as a sum of positive squares in 2 ways, for example, as 306916 + 2331729 = 554^2 + 1527^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638645 - 2⁵ = 2638613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2638645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263860 + ... + 263869.

It is an arithmetic number, because the mean of its divisors is an integer number (791595).

2^2638645 is an apocalyptic number.

It is an amenable number.

2638645 is a deficient number, since it is larger than the sum of its proper divisors (527735).

2638645 is an equidigital number, since it uses as much as digits as its factorization.

2638645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527734.

The product of its digits is 34560, while the sum is 34.

The square root of 2638645 is about 1624.3906549842. The cubic root of 2638645 is about 138.1848150398.

The spelling of 2638645 in words is "two million, six hundred thirty-eight thousand, six hundred forty-five".