257409493 has 4 divisors (see below), whose sum is σ = 280810368. Its totient is φ = 234008620.

The previous prime is 257409457. The next prime is 257409497. The reversal of 257409493 is 394904752.

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 a de Polignac number, because none of the positive numbers 2^k-257409493 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 (257409497) 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, 11700421 + ... + 11700442.

It is an arithmetic number, because the mean of its divisors is an integer number (70202592).

Almost surely, 2^257409493 is an apocalyptic number.

It is an amenable number.

257409493 is a deficient number, since it is larger than the sum of its proper divisors (23400875).

257409493 is a wasteful number, since it uses less digits than its factorization.

257409493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23400874.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 257409493 is about 16043.9861942100. The cubic root of 257409493 is about 636.1236170787.

The spelling of 257409493 in words is "two hundred fifty-seven million, four hundred nine thousand, four hundred ninety-three".