2581645 has 16 divisors (see below), whose sum is σ = 3431232. Its totient is φ = 1848960.

The previous prime is 2581643. The next prime is 2581651. The reversal of 2581645 is 5461852.

2581645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2581645 - 2¹ = 2581643 is a prime.

It is a super-3 number, since 3×2581645³ = 51619146849254733375, which contains 333 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3694 + ... + 4336.

It is an arithmetic number, because the mean of its divisors is an integer number (214452).

2^2581645 is an apocalyptic number.

It is an amenable number.

2581645 is a deficient number, since it is larger than the sum of its proper divisors (849587).

2581645 is a wasteful number, since it uses less digits than its factorization.

2581645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732.

The product of its digits is 9600, while the sum is 31.

The square root of 2581645 is about 1606.7498249572. The cubic root of 2581645 is about 137.1825403413.

The spelling of 2581645 in words is "two million, five hundred eighty-one thousand, six hundred forty-five".