8561245729 has 9 divisors (see below), whose sum is σ = 8697230451. Its totient is φ = 8427359160.

The previous prime is 8561245723. The next prime is 8561245733. The reversal of 8561245729 is 9275421658.

The square root of 8561245729 is 92527.

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

It can be written as a sum of positive squares in only one way, i.e., 3890890129 + 4670355600 = 62377^2 + 68340^2 .

It is not a de Polignac number, because 8561245729 - 2¹⁹ = 8560721441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8561245723) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6198619 + ... + 6199999.

It is an arithmetic number, because the mean of its divisors is an integer number (966358939).

Almost surely, 2^8561245729 is an apocalyptic number.

8561245729 is the 92527-th square number.

8561245729 is the 46264-th centered octagonal number.

It is an amenable number.

8561245729 is a deficient number, since it is larger than the sum of its proper divisors (135984722).

8561245729 is an frugal number, since it uses more digits than its factorization.

8561245729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2896 (or 1448 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 49.

The cubic root of 8561245729 is about 2045.7174710457.

Multiplying 8561245729 by its sum of digits (49), we get a square (419501040721 = 647689²).

The spelling of 8561245729 in words is "eight billion, five hundred sixty-one million, two hundred forty-five thousand, seven hundred twenty-nine".