257878 has 4 divisors (see below), whose sum is σ = 386820. Its totient is φ = 128938.

The previous prime is 257869. The next prime is 257879. The reversal of 257878 is 878752.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64468 + ... + 64471.

It is an arithmetic number, because the mean of its divisors is an integer number (96705).

2²⁵⁷⁸⁷⁸ is an apocalyptic number.

257878 is a deficient number, since it is larger than the sum of its proper divisors (128942).

257878 is a wasteful number, since it uses less digits than its factorization.

257878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128941.

The product of its digits is 31360, while the sum is 37.

The square root of 257878 is about 507.8168961348. The cubic root of 257878 is about 63.6509316060.

The spelling of 257878 in words is "two hundred fifty-seven thousand, eight hundred seventy-eight".