2168666 has 4 divisors (see below), whose sum is σ = 3253002. Its totient is φ = 1084332.

The previous prime is 2168659. The next prime is 2168669. The reversal of 2168666 is 6668612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1256641 + 912025 = 1121^2 + 955^2 .

It is a super-2 number, since 2×2168666² = 9406224439112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2168669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 542165 + ... + 542168.

2^2168666 is an apocalyptic number.

2168666 is a deficient number, since it is larger than the sum of its proper divisors (1084336).

2168666 is a wasteful number, since it uses less digits than its factorization.

2168666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084335.

The product of its digits is 20736, while the sum is 35.

The square root of 2168666 is about 1472.6391275530. The cubic root of 2168666 is about 129.4387241597.

The spelling of 2168666 in words is "two million, one hundred sixty-eight thousand, six hundred sixty-six".