257057161565 has 4 divisors (see below), whose sum is σ = 308468593884. Its totient is φ = 205645729248.

The previous prime is 257057161549. The next prime is 257057161573. The reversal of 257057161565 is 565161750752.

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

It can be written as a sum of positive squares in 2 ways, for example, as 48768980569 + 208288180996 = 220837^2 + 456386^2 .

It is a cyclic number.

It is not a de Polignac number, because 257057161565 - 2⁴ = 257057161549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25705716152 + ... + 25705716161.

It is an arithmetic number, because the mean of its divisors is an integer number (77117148471).

Almost surely, 2^257057161565 is an apocalyptic number.

It is an amenable number.

257057161565 is a deficient number, since it is larger than the sum of its proper divisors (51411432319).

257057161565 is an equidigital number, since it uses as much as digits as its factorization.

257057161565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51411432318.

The product of its (nonzero) digits is 2205000, while the sum is 50.

The spelling of 257057161565 in words is "two hundred fifty-seven billion, fifty-seven million, one hundred sixty-one thousand, five hundred sixty-five".