2556406666 has 32 divisors (see below), whose sum is σ = 4398468480. Its totient is φ = 1103524800.

The previous prime is 2556406663. The next prime is 2556406667. The reversal of 2556406666 is 6666046552.

It is not an unprimeable number, because it can be changed into a prime (2556406663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6075 + ... + 71761.

It is an arithmetic number, because the mean of its divisors is an integer number (137452140).

Almost surely, 2^2556406666 is an apocalyptic number.

2556406666 is a deficient number, since it is larger than the sum of its proper divisors (1842061814).

2556406666 is a wasteful number, since it uses less digits than its factorization.

2556406666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65790.

The product of its (nonzero) digits is 1555200, while the sum is 46.

The square root of 2556406666 is about 50560.9203436805. The cubic root of 2556406666 is about 1367.3404040226.

The spelling of 2556406666 in words is "two billion, five hundred fifty-six million, four hundred six thousand, six hundred sixty-six".