2581365 has 32 divisors (see below), whose sum is σ = 4478976. Its totient is φ = 1264640.

The previous prime is 2581357. The next prime is 2581367. The reversal of 2581365 is 5631852.

It is not a de Polignac number, because 2581365 - 2³ = 2581357 is a prime.

2581365 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13420 + ... + 13610.

It is an arithmetic number, because the mean of its divisors is an integer number (139968).

2^2581365 is an apocalyptic number.

It is an amenable number.

2581365 is a deficient number, since it is larger than the sum of its proper divisors (1897611).

2581365 is a wasteful number, since it uses less digits than its factorization.

2581365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269.

The product of its digits is 7200, while the sum is 30.

The square root of 2581365 is about 1606.6626901749. The cubic root of 2581365 is about 137.1775806483.

It can be divided in two parts, 25813 and 65, that added together give a triangular number (25878 = T₂₂₇).

The spelling of 2581365 in words is "two million, five hundred eighty-one thousand, three hundred sixty-five".