8257385581 has 2 divisors, whose sum is σ = 8257385582. Its totient is φ = 8257385580.

The previous prime is 8257385573. The next prime is 8257385621. The reversal of 8257385581 is 1855837528.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5225121225 + 3032264356 = 72285^2 + 55066^2 .

It is a cyclic number.

It is not a de Polignac number, because 8257385581 - 2³ = 8257385573 is a prime.

It is a super-2 number, since 2×8257385581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8257385501) 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 as a sum of consecutive naturals, namely, 4128692790 + 4128692791.

It is an arithmetic number, because the mean of its divisors is an integer number (4128692791).

Almost surely, 2^8257385581 is an apocalyptic number.

It is an amenable number.

8257385581 is a deficient number, since it is larger than the sum of its proper divisors (1).

8257385581 is an equidigital number, since it uses as much as digits as its factorization.

8257385581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688000, while the sum is 52.

The square root of 8257385581 is about 90870.1578132227. The cubic root of 8257385581 is about 2021.2227982587. Note that the first 3 decimals are identical.

The spelling of 8257385581 in words is "eight billion, two hundred fifty-seven million, three hundred eighty-five thousand, five hundred eighty-one".