257507139 has 4 divisors (see below), whose sum is σ = 343342856. Its totient is φ = 171671424.

The previous prime is 257507137. The next prime is 257507167. The reversal of 257507139 is 931705752.

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

It is not a de Polignac number, because 257507139 - 2¹ = 257507137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 257507097 and 257507106.

It is not an unprimeable number, because it can be changed into a prime (257507137) 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, 42917854 + ... + 42917859.

It is an arithmetic number, because the mean of its divisors is an integer number (85835714).

Almost surely, 2^257507139 is an apocalyptic number.

257507139 is a deficient number, since it is larger than the sum of its proper divisors (85835717).

257507139 is an equidigital number, since it uses as much as digits as its factorization.

257507139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85835716.

The product of its (nonzero) digits is 66150, while the sum is 39.

The square root of 257507139 is about 16047.0289773528. The cubic root of 257507139 is about 636.2040428540.

The spelling of 257507139 in words is "two hundred fifty-seven million, five hundred seven thousand, one hundred thirty-nine".