257128747 has 2 divisors, whose sum is σ = 257128748. Its totient is φ = 257128746.

The previous prime is 257128741. The next prime is 257128759. The reversal of 257128747 is 747821752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257128747 - 2¹¹ = 257126699 is a prime.

It is a super-2 number, since 2×257128747² = 132230385067580018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257128741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128564373 + 128564374.

It is an arithmetic number, because the mean of its divisors is an integer number (128564374).

Almost surely, 2^257128747 is an apocalyptic number.

257128747 is a deficient number, since it is larger than the sum of its proper divisors (1).

257128747 is an equidigital number, since it uses as much as digits as its factorization.

257128747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 219520, while the sum is 43.

The square root of 257128747 is about 16035.2345477077. The cubic root of 257128747 is about 635.8922682851.

The spelling of 257128747 in words is "two hundred fifty-seven million, one hundred twenty-eight thousand, seven hundred forty-seven".