85683521721 has 32 divisors (see below), whose sum is σ = 132184700928. Its totient is φ = 48355176960.

The previous prime is 85683521699. The next prime is 85683521797. The reversal of 85683521721 is 12712538658.

It is not a de Polignac number, because 85683521721 - 2¹⁰ = 85683520697 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (85683521621) 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 31 ways as a sum of consecutive naturals, for example, 6297636 + ... + 6311226.

It is an arithmetic number, because the mean of its divisors is an integer number (4130771904).

Almost surely, 2^85683521721 is an apocalyptic number.

It is an amenable number.

85683521721 is a deficient number, since it is larger than the sum of its proper divisors (46501179207).

85683521721 is a wasteful number, since it uses less digits than its factorization.

85683521721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17301.

The product of its digits is 806400, while the sum is 48.

The spelling of 85683521721 in words is "eighty-five billion, six hundred eighty-three million, five hundred twenty-one thousand, seven hundred twenty-one".