2563865 has 8 divisors (see below), whose sum is σ = 3094728. Its totient is φ = 2039040.

The previous prime is 2563859. The next prime is 2563867. The reversal of 2563865 is 5683652.

It can be written as a sum of positive squares in 4 ways, for example, as 13456 + 2550409 = 116^2 + 1597^2 .

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

It is not a de Polignac number, because 2563865 - 2⁴ = 2563849 is a prime.

It is a d-powerful number, because it can be written as 2¹⁹ + 5⁷ + 6² + 3 + 8³ + 6⁵ + 5⁹ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2563867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512 + ... + 2321.

It is an arithmetic number, because the mean of its divisors is an integer number (386841).

2^2563865 is an apocalyptic number.

It is an amenable number.

2563865 is a deficient number, since it is larger than the sum of its proper divisors (530863).

2563865 is a wasteful number, since it uses less digits than its factorization.

2563865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3019.

The product of its digits is 43200, while the sum is 35.

The square root of 2563865 is about 1601.2073569654. The cubic root of 2563865 is about 136.8668854610.

The spelling of 2563865 in words is "two million, five hundred sixty-three thousand, eight hundred sixty-five".