8521547650561 has 27 divisors (see below), whose sum is σ = 9701845805379. Its totient is φ = 7478910978000.

The previous prime is 8521547650493. The next prime is 8521547650591. The reversal of 8521547650561 is 1650567451258.

The square root of 8521547650561 is 2919169.

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., 4468492882161 + 4053054768400 = 2113881^2 + 2013220^2 .

It is not a de Polignac number, because 8521547650561 - 2²⁹ = 8521010779649 is a prime.

It is a super-2 number, since 2×8521547650561² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8521547650591) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 931210336 + ... + 931219486.

Almost surely, 2^{8521547650561} is an apocalyptic number.

8521547650561 is the 2919169-th square number.

8521547650561 is the 1459585-th centered octagonal number.

It is an amenable number.

8521547650561 is a deficient number, since it is larger than the sum of its proper divisors (1180298154818).

8521547650561 is an frugal number, since it uses more digits than its factorization.

8521547650561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18382 (or 9191 counting only the distinct ones).

The product of its (nonzero) digits is 10080000, while the sum is 55.

The spelling of 8521547650561 in words is "eight trillion, five hundred twenty-one billion, five hundred forty-seven million, six hundred fifty thousand, five hundred sixty-one".