2556668 has 6 divisors (see below), whose sum is σ = 4474176. Its totient is φ = 1278332.

The previous prime is 2556661. The next prime is 2556683. The reversal of 2556668 is 8666552.

It is a happy number.

2556668 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a d-powerful number, because it can be written as 2 + 5⁵ + 5⁹ + 6⁵ + 6⁷ + 6⁷ + 8⁵ .

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556661) 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, 319580 + ... + 319587.

It is an arithmetic number, because the mean of its divisors is an integer number (745696).

2^2556668 is an apocalyptic number.

It is an amenable number.

2556668 is a deficient number, since it is larger than the sum of its proper divisors (1917508).

2556668 is a wasteful number, since it uses less digits than its factorization.

2556668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639171 (or 639169 counting only the distinct ones).

The product of its digits is 86400, while the sum is 38.

The square root of 2556668 is about 1598.9584109663. The cubic root of 2556668 is about 136.7386995509.

The spelling of 2556668 in words is "two million, five hundred fifty-six thousand, six hundred sixty-eight".