257284490581 has 2 divisors, whose sum is σ = 257284490582. Its totient is φ = 257284490580.

The previous prime is 257284490539. The next prime is 257284490591. The reversal of 257284490581 is 185094482752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 254006928081 + 3277562500 = 503991^2 + 57250^2 .

It is a cyclic number.

It is not a de Polignac number, because 257284490581 - 2⁷ = 257284490453 is a prime.

It is a super-2 number, since 2×257284490581² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257284490501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128642245290 + 128642245291.

It is an arithmetic number, because the mean of its divisors is an integer number (128642245291).

Almost surely, 2^257284490581 is an apocalyptic number.

It is an amenable number.

257284490581 is a deficient number, since it is larger than the sum of its proper divisors (1).

257284490581 is an equidigital number, since it uses as much as digits as its factorization.

257284490581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6451200, while the sum is 55.

The spelling of 257284490581 in words is "two hundred fifty-seven billion, two hundred eighty-four million, four hundred ninety thousand, five hundred eighty-one".