257641 has 4 divisors (see below), whose sum is σ = 265984. Its totient is φ = 249300.

The previous prime is 257639. The next prime is 257657. The reversal of 257641 is 146752.

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 257641 - 2¹ = 257639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4125 + ... + 4186.

It is an arithmetic number, because the mean of its divisors is an integer number (66496).

2²⁵⁷⁶⁴¹ is an apocalyptic number.

It is an amenable number.

257641 is a deficient number, since it is larger than the sum of its proper divisors (8343).

257641 is an equidigital number, since it uses as much as digits as its factorization.

257641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8342.

The product of its digits is 1680, while the sum is 25.

The square root of 257641 is about 507.5834906693. The cubic root of 257641 is about 63.6314263949.

Subtracting from 257641 its reverse (146752), we obtain a square (110889 = 333²).

It can be divided in two parts, 257 and 641, that added together give a palindrome (898).

The spelling of 257641 in words is "two hundred fifty-seven thousand, six hundred forty-one".