257249647 has 2 divisors, whose sum is σ = 257249648. Its totient is φ = 257249646.

The previous prime is 257249609. The next prime is 257249711. The reversal of 257249647 is 746942752.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257249647 - 2¹⁵ = 257216879 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 257249597 and 257249606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257249347) 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, 128624823 + 128624824.

It is an arithmetic number, because the mean of its divisors is an integer number (128624824).

Almost surely, 2^257249647 is an apocalyptic number.

257249647 is a deficient number, since it is larger than the sum of its proper divisors (1).

257249647 is an equidigital number, since it uses as much as digits as its factorization.

257249647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 46.

The square root of 257249647 is about 16039.0039279252. The cubic root of 257249647 is about 635.9919165870.

The spelling of 257249647 in words is "two hundred fifty-seven million, two hundred forty-nine thousand, six hundred forty-seven".