256871187 has 6 divisors (see below), whose sum is σ = 371036172. Its totient is φ = 171247452.

The previous prime is 256871171. The next prime is 256871201. The reversal of 256871187 is 781178652.

It is a happy number.

256871187 is a `hidden beast` number, since 2 + 568 + 7 + 1 + 1 + 87 = 666.

It is not a de Polignac number, because 256871187 - 2⁴ = 256871171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256871117) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14270613 + ... + 14270630.

It is an arithmetic number, because the mean of its divisors is an integer number (61839362).

Almost surely, 2^256871187 is an apocalyptic number.

256871187 is a deficient number, since it is larger than the sum of its proper divisors (114164985).

256871187 is a wasteful number, since it uses less digits than its factorization.

256871187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28541249 (or 28541246 counting only the distinct ones).

The product of its digits is 188160, while the sum is 45.

The square root of 256871187 is about 16027.2014712488. The cubic root of 256871187 is about 635.6798777609.

The spelling of 256871187 in words is "two hundred fifty-six million, eight hundred seventy-one thousand, one hundred eighty-seven".