257740345 has 4 divisors (see below), whose sum is σ = 309288420. Its totient is φ = 206192272.

The previous prime is 257740319. The next prime is 257740361. The reversal of 257740345 is 543047752.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 169624576 + 88115769 = 13024^2 + 9387^2 .

It is a cyclic number.

It is not a de Polignac number, because 257740345 - 2¹⁵ = 257707577 is a prime.

It is an unprimeable number.

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, 25774030 + ... + 25774039.

It is an arithmetic number, because the mean of its divisors is an integer number (77322105).

Almost surely, 2^257740345 is an apocalyptic number.

It is an amenable number.

257740345 is a deficient number, since it is larger than the sum of its proper divisors (51548075).

257740345 is an equidigital number, since it uses as much as digits as its factorization.

257740345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51548074.

The product of its (nonzero) digits is 117600, while the sum is 37.

The square root of 257740345 is about 16054.2936624443. The cubic root of 257740345 is about 636.3960399053.

The spelling of 257740345 in words is "two hundred fifty-seven million, seven hundred forty thousand, three hundred forty-five".