257042821 has 8 divisors (see below), whose sum is σ = 293863680. Its totient is φ = 220247088.

The previous prime is 257042809. The next prime is 257042833. The reversal of 257042821 is 128240752.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (257042809) and next prime (257042833).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257042821 - 2⁵ = 257042789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257042801) 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 in 7 ways as a sum of consecutive naturals, for example, 28500 + ... + 36418.

It is an arithmetic number, because the mean of its divisors is an integer number (36732960).

Almost surely, 2^257042821 is an apocalyptic number.

It is an amenable number.

257042821 is a deficient number, since it is larger than the sum of its proper divisors (36820859).

257042821 is an equidigital number, since it uses as much as digits as its factorization.

257042821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12563.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 257042821 is about 16032.5550365499. Note that the first 3 decimals coincide. The cubic root of 257042821 is about 635.8214272930.

The spelling of 257042821 in words is "two hundred fifty-seven million, forty-two thousand, eight hundred twenty-one".