256525666 has 4 divisors (see below), whose sum is σ = 384788502. Its totient is φ = 128262832.

The previous prime is 256525657. The next prime is 256525691. The reversal of 256525666 is 666525652.

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., 178997641 + 77528025 = 13379^2 + 8805^2 .

It is an unprimeable number.

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, 64131415 + ... + 64131418.

Almost surely, 2^256525666 is an apocalyptic number.

256525666 is a deficient number, since it is larger than the sum of its proper divisors (128262836).

256525666 is a wasteful number, since it uses less digits than its factorization.

256525666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128262835.

The product of its digits is 648000, while the sum is 43.

The square root of 256525666 is about 16016.4186383848. The cubic root of 256525666 is about 635.3947292605.

The spelling of 256525666 in words is "two hundred fifty-six million, five hundred twenty-five thousand, six hundred sixty-six".