257425209 has 32 divisors (see below), whose sum is σ = 398638080. Its totient is φ = 166037040.

The previous prime is 257425171. The next prime is 257425249. The reversal of 257425209 is 902524752.

It is a happy number.

257425209 is a `hidden beast` number, since 25 + 7 + 425 + 209 = 666.

It is not a de Polignac number, because 257425209 - 2⁸ = 257424953 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (257425249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65899 + ... + 69695.

It is an arithmetic number, because the mean of its divisors is an integer number (12457440).

Almost surely, 2^257425209 is an apocalyptic number.

It is an amenable number.

257425209 is a deficient number, since it is larger than the sum of its proper divisors (141212871).

257425209 is an frugal number, since it uses more digits than its factorization.

257425209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3849 (or 3831 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 257425209 is about 16044.4759652661. The cubic root of 257425209 is about 636.1365628785.

The spelling of 257425209 in words is "two hundred fifty-seven million, four hundred twenty-five thousand, two hundred nine".