2638865 has 8 divisors (see below), whose sum is σ = 3175848. Its totient is φ = 2104960.

The previous prime is 2638849. The next prime is 2638873. The reversal of 2638865 is 5688362.

It can be written as a sum of positive squares in 4 ways, for example, as 66049 + 2572816 = 257^2 + 1604^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2638865 - 2⁴ = 2638849 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2099 + ... + 3111.

It is an arithmetic number, because the mean of its divisors is an integer number (396981).

2^2638865 is an apocalyptic number.

It is an amenable number.

2638865 is a deficient number, since it is larger than the sum of its proper divisors (536983).

2638865 is a wasteful number, since it uses less digits than its factorization.

2638865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539.

The product of its digits is 69120, while the sum is 38.

The square root of 2638865 is about 1624.4583712733. The cubic root of 2638865 is about 138.1886553713.

The spelling of 2638865 in words is "two million, six hundred thirty-eight thousand, eight hundred sixty-five".