257161405 has 4 divisors (see below), whose sum is σ = 308593692. Its totient is φ = 205729120.

The previous prime is 257161403. The next prime is 257161417. The reversal of 257161405 is 504161752.

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 179051161 + 78110244 = 13381^2 + 8838^2 .

It is not a de Polignac number, because 257161405 - 2¹ = 257161403 is a prime.

It is a super-2 number, since 2×257161405² = 132263976443148050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257161403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25716136 + ... + 25716145.

It is an arithmetic number, because the mean of its divisors is an integer number (77148423).

Almost surely, 2^257161405 is an apocalyptic number.

It is an amenable number.

257161405 is a deficient number, since it is larger than the sum of its proper divisors (51432287).

257161405 is an equidigital number, since it uses as much as digits as its factorization.

257161405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51432286.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 257161405 is about 16036.2528353727. The cubic root of 257161405 is about 635.9191887686.

The spelling of 257161405 in words is "two hundred fifty-seven million, one hundred sixty-one thousand, four hundred five".