2581643 has 2 divisors, whose sum is σ = 2581644. Its totient is φ = 2581642.

The previous prime is 2581639. The next prime is 2581651. The reversal of 2581643 is 3461852.

2581643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2581643 - 2² = 2581639 is a prime.

It is not a weakly prime, because it can be changed into another prime (2581613) 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 as a sum of consecutive naturals, namely, 1290821 + 1290822.

It is an arithmetic number, because the mean of its divisors is an integer number (1290822).

2^2581643 is an apocalyptic number.

2581643 is a deficient number, since it is larger than the sum of its proper divisors (1).

2581643 is an equidigital number, since it uses as much as digits as its factorization.

2581643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 29.

The square root of 2581643 is about 1606.7492025827. The cubic root of 2581643 is about 137.1825049162.

The spelling of 2581643 in words is "two million, five hundred eighty-one thousand, six hundred forty-three".