257445 has 16 divisors (see below), whose sum is σ = 457920. Its totient is φ = 137232.

The previous prime is 257443. The next prime is 257447. The reversal of 257445 is 544752.

It is an interprime number because it is at equal distance from previous prime (257443) and next prime (257447).

It is not a de Polignac number, because 257445 - 2¹ = 257443 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819 + ... + 1088.

It is an arithmetic number, because the mean of its divisors is an integer number (28620).

2²⁵⁷⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

257445 is a deficient number, since it is larger than the sum of its proper divisors (200475).

257445 is a wasteful number, since it uses less digits than its factorization.

257445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1921 (or 1915 counting only the distinct ones).

The product of its digits is 5600, while the sum is 27.

The square root of 257445 is about 507.3903822502. The cubic root of 257445 is about 63.6152864644.

The spelling of 257445 in words is "two hundred fifty-seven thousand, four hundred forty-five".