256681843507183 has 4 divisors (see below), whose sum is σ = 259328048079520. Its totient is φ = 254035638934848.

The previous prime is 256681843507169. The next prime is 256681843507267. The reversal of 256681843507183 is 381705348186652.

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

It is a cyclic number.

It is not a de Polignac number, because 256681843507183 - 2²¹ = 256681841410031 is a prime.

It is a super-2 number, since 2×256681843507183² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256681843507483) 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, 1323102286023 + ... + 1323102286216.

It is an arithmetic number, because the mean of its divisors is an integer number (64832012019880).

Almost surely, 2^{256681843507183} is an apocalyptic number.

256681843507183 is a deficient number, since it is larger than the sum of its proper divisors (2646204572337).

256681843507183 is an equidigital number, since it uses as much as digits as its factorization.

256681843507183 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2646204572336.

The product of its (nonzero) digits is 232243200, while the sum is 67.

The spelling of 256681843507183 in words is "two hundred fifty-six trillion, six hundred eighty-one billion, eight hundred forty-three million, five hundred seven thousand, one hundred eighty-three".