256581194 has 4 divisors (see below), whose sum is σ = 384871794. Its totient is φ = 128290596.

The previous prime is 256581191. The next prime is 256581209. The reversal of 256581194 is 491185652.

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., 130804969 + 125776225 = 11437^2 + 11215^2 .

It is a super-2 number, since 2×256581194² = 131667818228931272, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256581191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64145297 + ... + 64145300.

Almost surely, 2^256581194 is an apocalyptic number.

256581194 is a deficient number, since it is larger than the sum of its proper divisors (128290600).

256581194 is a wasteful number, since it uses less digits than its factorization.

256581194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128290599.

The product of its digits is 86400, while the sum is 41.

The square root of 256581194 is about 16018.1520157601. The cubic root of 256581194 is about 635.4405721757.

The spelling of 256581194 in words is "two hundred fifty-six million, five hundred eighty-one thousand, one hundred ninety-four".