257506981 has 8 divisors (see below), whose sum is σ = 273041280. Its totient is φ = 242170848.

The previous prime is 257506961. The next prime is 257507009. The reversal of 257506981 is 189605752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257506981 - 2¹³ = 257498789 is a prime.

It is a super-2 number, since 2×257506981² = 132619690527468722, 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 (257506961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46861 + ... + 52066.

It is an arithmetic number, because the mean of its divisors is an integer number (34130160).

Almost surely, 2^257506981 is an apocalyptic number.

It is an amenable number.

257506981 is a deficient number, since it is larger than the sum of its proper divisors (15534299).

257506981 is a wasteful number, since it uses less digits than its factorization.

257506981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99083.

The product of its (nonzero) digits is 151200, while the sum is 43.

The square root of 257506981 is about 16047.0240543223. The cubic root of 257506981 is about 636.2039127343.

The spelling of 257506981 in words is "two hundred fifty-seven million, five hundred six thousand, nine hundred eighty-one".