257745641 has 4 divisors (see below), whose sum is σ = 257779284. Its totient is φ = 257712000.

The previous prime is 257745581. The next prime is 257745647. The reversal of 257745641 is 146547752.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 41538025 + 216207616 = 6445^2 + 14704^2 .

It is a cyclic number.

It is not a de Polignac number, because 257745641 - 2⁶ = 257745577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257745647) 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, 881 + ... + 22721.

It is an arithmetic number, because the mean of its divisors is an integer number (64444821).

Almost surely, 2^257745641 is an apocalyptic number.

It is an amenable number.

257745641 is a deficient number, since it is larger than the sum of its proper divisors (33643).

257745641 is a wasteful number, since it uses less digits than its factorization.

257745641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33642.

The product of its digits is 235200, while the sum is 41.

The square root of 257745641 is about 16054.4586018962. The cubic root of 257745641 is about 636.4003987241.

The spelling of 257745641 in words is "two hundred fifty-seven million, seven hundred forty-five thousand, six hundred forty-one".