85011771581 has 16 divisors (see below), whose sum is σ = 93517744320. Its totient is φ = 76636721280.

The previous prime is 85011771557. The next prime is 85011771583. The reversal of 85011771581 is 18517711058.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85011771581 is a prime.

It is a super-2 number, since 2×85011771581² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85011771583) 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 in 15 ways as a sum of consecutive naturals, for example, 1277915 + ... + 1342791.

It is an arithmetic number, because the mean of its divisors is an integer number (5844859020).

Almost surely, 2^85011771581 is an apocalyptic number.

It is an amenable number.

85011771581 is a deficient number, since it is larger than the sum of its proper divisors (8505972739).

85011771581 is a wasteful number, since it uses less digits than its factorization.

85011771581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65884.

The product of its (nonzero) digits is 78400, while the sum is 44.

The spelling of 85011771581 in words is "eighty-five billion, eleven million, seven hundred seventy-one thousand, five hundred eighty-one".