256540178 has 4 divisors (see below), whose sum is σ = 384810270. Its totient is φ = 128270088.

The previous prime is 256540153. The next prime is 256540181. The reversal of 256540178 is 871045652.

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., 174583369 + 81956809 = 13213^2 + 9053^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64135043 + ... + 64135046.

Almost surely, 2^256540178 is an apocalyptic number.

256540178 is a deficient number, since it is larger than the sum of its proper divisors (128270092).

256540178 is a wasteful number, since it uses less digits than its factorization.

256540178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128270091.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 256540178 is about 16016.8716670891. The cubic root of 256540178 is about 635.4067107444.

The spelling of 256540178 in words is "two hundred fifty-six million, five hundred forty thousand, one hundred seventy-eight".