257208381 has 6 divisors (see below), whose sum is σ = 371523230. Its totient is φ = 171472248.

The previous prime is 257208373. The next prime is 257208403. The reversal of 257208381 is 183802752.

257208381 is a `hidden beast` number, since 2 + 572 + 0 + 8 + 3 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 254913156 + 2295225 = 15966^2 + 1515^2 .

It is not a de Polignac number, because 257208381 - 2³ = 257208373 is a prime.

It is a super-2 number, since 2×257208381² = 132312302513282322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257208331) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14289346 + ... + 14289363.

Almost surely, 2^257208381 is an apocalyptic number.

It is an amenable number.

257208381 is a deficient number, since it is larger than the sum of its proper divisors (114314849).

257208381 is a wasteful number, since it uses less digits than its factorization.

257208381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28578715 (or 28578712 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 257208381 is about 16037.7174498119. The cubic root of 257208381 is about 635.9579077993.

The spelling of 257208381 in words is "two hundred fifty-seven million, two hundred eight thousand, three hundred eighty-one".