256711555 has 4 divisors (see below), whose sum is σ = 308053872. Its totient is φ = 205369240.

The previous prime is 256711549. The next prime is 256711561. The reversal of 256711555 is 555117652.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (256711549) and next prime (256711561).

It is not a de Polignac number, because 256711555 - 2³ = 256711547 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25671151 + ... + 25671160.

It is an arithmetic number, because the mean of its divisors is an integer number (77013468).

Almost surely, 2^256711555 is an apocalyptic number.

256711555 is a deficient number, since it is larger than the sum of its proper divisors (51342317).

256711555 is an equidigital number, since it uses as much as digits as its factorization.

256711555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51342316.

The product of its digits is 52500, while the sum is 37.

The square root of 256711555 is about 16022.2206638156. The cubic root of 256711555 is about 635.5481698815.

The spelling of 256711555 in words is "two hundred fifty-six million, seven hundred eleven thousand, five hundred fifty-five".