8505081729 has 15 divisors (see below), whose sum is σ = 12706362097. Its totient is φ = 5669501148.

The previous prime is 8505081719. The next prime is 8505081731. The reversal of 8505081729 is 9271805058.

It is a happy number.

The square root of 8505081729 is 92223.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 8505081729 - 2¹⁵ = 8505048961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8505081719) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 824884 + ... + 835130.

Almost surely, 2^8505081729 is an apocalyptic number.

8505081729 is the 92223-rd square number.

8505081729 is the 46112-nd centered octagonal number.

It is an amenable number.

8505081729 is a deficient number, since it is larger than the sum of its proper divisors (4201280368).

8505081729 is an frugal number, since it uses more digits than its factorization.

8505081729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20506 (or 10250 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The cubic root of 8505081729 is about 2041.2341731736.

The spelling of 8505081729 in words is "eight billion, five hundred five million, eighty-one thousand, seven hundred twenty-nine".