256666066 has 16 divisors (see below), whose sum is σ = 398831040. Its totient is φ = 123734800.

The previous prime is 256666057. The next prime is 256666093. The reversal of 256666066 is 660666652.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45291 + ... + 50641.

It is an arithmetic number, because the mean of its divisors is an integer number (24926940).

Almost surely, 2^256666066 is an apocalyptic number.

256666066 is a deficient number, since it is larger than the sum of its proper divisors (142164974).

256666066 is a wasteful number, since it uses less digits than its factorization.

256666066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6209.

The product of its (nonzero) digits is 466560, while the sum is 43.

The square root of 256666066 is about 16020.8010411465. The cubic root of 256666066 is about 635.5106281894.

The spelling of 256666066 in words is "two hundred fifty-six million, six hundred sixty-six thousand, sixty-six".