85839581 has 2 divisors, whose sum is σ = 85839582. Its totient is φ = 85839580.

The previous prime is 85839577. The next prime is 85839617. The reversal of 85839581 is 18593858.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71132356 + 14707225 = 8434^2 + 3835^2 .

It is a cyclic number.

It is not a de Polignac number, because 85839581 - 2² = 85839577 is a prime.

It is a super-2 number, since 2×85839581² = 14736867332511122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85139581) 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 as a sum of consecutive naturals, namely, 42919790 + 42919791.

It is an arithmetic number, because the mean of its divisors is an integer number (42919791).

Almost surely, 2^85839581 is an apocalyptic number.

It is an amenable number.

85839581 is a deficient number, since it is larger than the sum of its proper divisors (1).

85839581 is an equidigital number, since it uses as much as digits as its factorization.

85839581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 47.

The square root of 85839581 is about 9264.9652454826. The cubic root of 85839581 is about 441.1258718277.

The spelling of 85839581 in words is "eighty-five million, eight hundred thirty-nine thousand, five hundred eighty-one".