85171521 has 16 divisors (see below), whose sum is σ = 120657600. Its totient is φ = 53339328.

The previous prime is 85171451. The next prime is 85171523. The reversal of 85171521 is 12517158.

It is not a de Polignac number, because 85171521 - 2¹⁰ = 85170497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (85171523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10011 + ... + 16448.

It is an arithmetic number, because the mean of its divisors is an integer number (7541100).

Almost surely, 2^85171521 is an apocalyptic number.

It is an amenable number.

85171521 is a deficient number, since it is larger than the sum of its proper divisors (35486079).

85171521 is a wasteful number, since it uses less digits than its factorization.

85171521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26528.

The product of its digits is 2800, while the sum is 30.

The square root of 85171521 is about 9228.8418016564. The cubic root of 85171521 is about 439.9785130692.

Adding to 85171521 its reverse (12517158), we get a palindrome (97688679).

The spelling of 85171521 in words is "eighty-five million, one hundred seventy-one thousand, five hundred twenty-one".