256756642471117 has 4 divisors (see below), whose sum is σ = 256756674572860. Its totient is φ = 256756610369376.

The previous prime is 256756642471111. The next prime is 256756642471141. The reversal of 256756642471117 is 711174246657652.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 211709309454756 + 45047333016361 = 14550234^2 + 6711731^2 .

It is a cyclic number.

It is not a de Polignac number, because 256756642471117 - 2⁷ = 256756642470989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256756642471111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6623263 + ... + 23608915.

It is an arithmetic number, because the mean of its divisors is an integer number (64189168643215).

Almost surely, 2^{256756642471117} is an apocalyptic number.

It is an amenable number.

256756642471117 is a deficient number, since it is larger than the sum of its proper divisors (32101743).

256756642471117 is a wasteful number, since it uses less digits than its factorization.

256756642471117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32101742.

The product of its digits is 118540800, while the sum is 64.

The spelling of 256756642471117 in words is "two hundred fifty-six trillion, seven hundred fifty-six billion, six hundred forty-two million, four hundred seventy-one thousand, one hundred seventeen".