2555666 has 4 divisors (see below), whose sum is σ = 3833502. Its totient is φ = 1277832.

The previous prime is 2555647. The next prime is 2555669. The reversal of 2555666 is 6665552.

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., 2418025 + 137641 = 1555^2 + 371^2 .

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (2555669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638915 + ... + 638918.

2^2555666 is an apocalyptic number.

2555666 is a deficient number, since it is larger than the sum of its proper divisors (1277836).

2555666 is a wasteful number, since it uses less digits than its factorization.

2555666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1277835.

The product of its digits is 54000, while the sum is 35.

The square root of 2555666 is about 1598.6450512856. The cubic root of 2555666 is about 136.7208338393.

The spelling of 2555666 in words is "two million, five hundred fifty-five thousand, six hundred sixty-six".