257421513 has 4 divisors (see below), whose sum is σ = 343228688. Its totient is φ = 171614340.

The previous prime is 257421509. The next prime is 257421517. The reversal of 257421513 is 315124752.

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 an interprime number because it is at equal distance from previous prime (257421509) and next prime (257421517).

It is not a de Polignac number, because 257421513 - 2² = 257421509 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257421517) 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, 42903583 + ... + 42903588.

It is an arithmetic number, because the mean of its divisors is an integer number (85807172).

Almost surely, 2^257421513 is an apocalyptic number.

It is an amenable number.

257421513 is a deficient number, since it is larger than the sum of its proper divisors (85807175).

257421513 is an equidigital number, since it uses as much as digits as its factorization.

257421513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85807174.

The product of its digits is 8400, while the sum is 30.

The square root of 257421513 is about 16044.3607850235. The cubic root of 257421513 is about 636.1335184059.

The spelling of 257421513 in words is "two hundred fifty-seven million, four hundred twenty-one thousand, five hundred thirteen".