2666661 has 4 divisors (see below), whose sum is σ = 3555552. Its totient is φ = 1777772.

The previous prime is 2666659. The next prime is 2666663. The reversal of 2666661 is 1666662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (2666659) and next prime (2666663).

It is a cyclic number.

It is not a de Polignac number, because 2666661 - 2¹ = 2666659 is a prime.

It is a super-2 number, since 2×2666661² = 14222161777842, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2666663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444441 + ... + 444446.

It is an arithmetic number, because the mean of its divisors is an integer number (888888).

2^2666661 is an apocalyptic number.

It is an amenable number.

2666661 is a deficient number, since it is larger than the sum of its proper divisors (888891).

2666661 is an equidigital number, since it uses as much as digits as its factorization.

2666661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888890.

The product of its digits is 15552, while the sum is 33.

The square root of 2666661 is about 1632.9914267993. The cubic root of 2666661 is about 138.6721566439.

Subtracting from 2666661 its reverse (1666662), we obtain a palindrome (999999).

The spelling of 2666661 in words is "two million, six hundred sixty-six thousand, six hundred sixty-one".