257085405 has 24 divisors (see below), whose sum is σ = 450216312. Its totient is φ = 135696384.

The previous prime is 257085379. The next prime is 257085461. The reversal of 257085405 is 504580752.

It is a happy number.

257085405 is a `hidden beast` number, since 2 + 570 + 85 + 4 + 0 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2268036 + 254817369 = 1506^2 + 15963^2 .

It is not a de Polignac number, because 257085405 - 2⁸ = 257085149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 257085405.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 25084 + ... + 33813.

It is an arithmetic number, because the mean of its divisors is an integer number (18759013).

Almost surely, 2^257085405 is an apocalyptic number.

It is an amenable number.

257085405 is a deficient number, since it is larger than the sum of its proper divisors (193130907).

257085405 is a wasteful number, since it uses less digits than its factorization.

257085405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59005 (or 59002 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 36.

The square root of 257085405 is about 16033.8830293850. The cubic root of 257085405 is about 635.8565372986.

It can be divided in two parts, 25708 and 5405, that added together give a palindrome (31113).

The spelling of 257085405 in words is "two hundred fifty-seven million, eighty-five thousand, four hundred five".