257385769 has 4 divisors (see below), whose sum is σ = 257418196. Its totient is φ = 257353344.

The previous prime is 257385743. The next prime is 257385781. The reversal of 257385769 is 967583752.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 60264169 + 197121600 = 7763^2 + 14040^2 .

It is a cyclic number.

It is not a de Polignac number, because 257385769 - 2⁷ = 257385641 is a prime.

It is a super-2 number, since 2×257385769² = 132494868167442722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257385719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4597 + ... + 23149.

It is an arithmetic number, because the mean of its divisors is an integer number (64354549).

Almost surely, 2^257385769 is an apocalyptic number.

It is an amenable number.

257385769 is a deficient number, since it is larger than the sum of its proper divisors (32427).

257385769 is a wasteful number, since it uses less digits than its factorization.

257385769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32426.

The product of its digits is 3175200, while the sum is 52.

The square root of 257385769 is about 16043.2468347277. The cubic root of 257385769 is about 636.1040738208.

The spelling of 257385769 in words is "two hundred fifty-seven million, three hundred eighty-five thousand, seven hundred sixty-nine".