257388613507 has 4 divisors (see below), whose sum is σ = 261751132440. Its totient is φ = 253026094576.

The previous prime is 257388613457. The next prime is 257388613511. The reversal of 257388613507 is 705316883752.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257388613507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257388613007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2181259378 + ... + 2181259495.

It is an arithmetic number, because the mean of its divisors is an integer number (65437783110).

Almost surely, 2^257388613507 is an apocalyptic number.

257388613507 is a deficient number, since it is larger than the sum of its proper divisors (4362518933).

257388613507 is an equidigital number, since it uses as much as digits as its factorization.

257388613507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4362518932.

The product of its (nonzero) digits is 8467200, while the sum is 55.

The spelling of 257388613507 in words is "two hundred fifty-seven billion, three hundred eighty-eight million, six hundred thirteen thousand, five hundred seven".