2666581 has 2 divisors, whose sum is σ = 2666582. Its totient is φ = 2666580.

The previous prime is 2666561. The next prime is 2666591. The reversal of 2666581 is 1856662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1380625 + 1285956 = 1175^2 + 1134^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666581 - 2⁷ = 2666453 is a prime.

It is a super-2 number, since 2×2666581² = 14221308459122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2666561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333290 + 1333291.

It is an arithmetic number, because the mean of its divisors is an integer number (1333291).

2^2666581 is an apocalyptic number.

It is an amenable number.

2666581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666581 is an equidigital number, since it uses as much as digits as its factorization.

2666581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 34.

The square root of 2666581 is about 1632.9669316921. The cubic root of 2666581 is about 138.6707699055.

The spelling of 2666581 in words is "two million, six hundred sixty-six thousand, five hundred eighty-one".