85857182581 has 2 divisors, whose sum is σ = 85857182582. Its totient is φ = 85857182580.

The previous prime is 85857182561. The next prime is 85857182623. The reversal of 85857182581 is 18528175858.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78643228356 + 7213954225 = 280434^2 + 84935^2 .

It is a cyclic number.

It is not a de Polignac number, because 85857182581 - 2⁹ = 85857182069 is a prime.

It is a super-2 number, since 2×85857182581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85857182561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42928591290 + 42928591291.

It is an arithmetic number, because the mean of its divisors is an integer number (42928591291).

Almost surely, 2^85857182581 is an apocalyptic number.

It is an amenable number.

85857182581 is a deficient number, since it is larger than the sum of its proper divisors (1).

85857182581 is an equidigital number, since it uses as much as digits as its factorization.

85857182581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7168000, while the sum is 58.

The spelling of 85857182581 in words is "eighty-five billion, eight hundred fifty-seven million, one hundred eighty-two thousand, five hundred eighty-one".