256109375257 has 8 divisors (see below), whose sum is σ = 270311581760. Its totient is φ = 241979445360.

The previous prime is 256109375233. The next prime is 256109375279. The reversal of 256109375257 is 752573901652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256109375257 - 2²³ = 256100986649 is a prime.

It is the 506073-rd Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256109375287) by changing a digit.

It is a nontrivial repunit in base 506072.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18061869 + ... + 18076042.

It is an arithmetic number, because the mean of its divisors is an integer number (33788947720).

Almost surely, 2^256109375257 is an apocalyptic number.

It is an amenable number.

256109375257 is a deficient number, since it is larger than the sum of its proper divisors (14202206503).

256109375257 is a wasteful number, since it uses less digits than its factorization.

256109375257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36138303.

The product of its (nonzero) digits is 3969000, while the sum is 52.

The spelling of 256109375257 in words is "two hundred fifty-six billion, one hundred nine million, three hundred seventy-five thousand, two hundred fifty-seven".