257728297 has 4 divisors (see below), whose sum is σ = 261575056. Its totient is φ = 253881540.

The previous prime is 257728267. The next prime is 257728357. The reversal of 257728297 is 792827752.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 257728297 - 2⁷ = 257728169 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 257728297.

It is not an unprimeable number, because it can be changed into a prime (257728267) 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 in 3 ways as a sum of consecutive naturals, for example, 1923279 + ... + 1923412.

It is an arithmetic number, because the mean of its divisors is an integer number (65393764).

Almost surely, 2^257728297 is an apocalyptic number.

It is an amenable number.

257728297 is a deficient number, since it is larger than the sum of its proper divisors (3846759).

257728297 is an equidigital number, since it uses as much as digits as its factorization.

257728297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3846758.

The product of its digits is 987840, while the sum is 49.

The square root of 257728297 is about 16053.9184313363. The cubic root of 257728297 is about 636.3861236995.

The spelling of 257728297 in words is "two hundred fifty-seven million, seven hundred twenty-eight thousand, two hundred ninety-seven".