256100557 has 2 divisors, whose sum is σ = 256100558. Its totient is φ = 256100556.

The previous prime is 256100543. The next prime is 256100587. The reversal of 256100557 is 755001652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 237961476 + 18139081 = 15426^2 + 4259^2 .

It is a cyclic number.

It is not a de Polignac number, because 256100557 - 2¹¹ = 256098509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256100527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128050278 + 128050279.

It is an arithmetic number, because the mean of its divisors is an integer number (128050279).

Almost surely, 2^256100557 is an apocalyptic number.

It is an amenable number.

256100557 is a deficient number, since it is larger than the sum of its proper divisors (1).

256100557 is an equidigital number, since it uses as much as digits as its factorization.

256100557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 256100557 is about 16003.1420977257. The cubic root of 256100557 is about 635.0435475539.

The spelling of 256100557 in words is "two hundred fifty-six million, one hundred thousand, five hundred fifty-seven".