9764568778561 has 9 divisors (see below), whose sum is σ = 10089815806179. Its totient is φ = 9449488944000.

The previous prime is 9764568778543. The next prime is 9764568778579. The reversal of 9764568778561 is 1658778654679.

The square root of 9764568778561 is 3124831.

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

9764568778561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (9764568778543) and next prime (9764568778579).

It can be written as a sum of positive squares in only one way, i.e., 193738561 + 9764375040000 = 13919^2 + 3124800^2 .

It is not a de Polignac number, because 9764568778561 - 2³⁵ = 9730209040193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9764568772561) 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, 96819361 + ... + 96920161.

It is an arithmetic number, because the mean of its divisors is an integer number (1121090645131).

Almost surely, 2^{9764568778561} is an apocalyptic number.

9764568778561 is the 3124831-st square number.

9764568778561 is the 1562416-th centered octagonal number.

It is an amenable number.

9764568778561 is a deficient number, since it is larger than the sum of its proper divisors (325247027618).

9764568778561 is an frugal number, since it uses more digits than its factorization.

9764568778561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201664 (or 100832 counting only the distinct ones).

The product of its digits is 4267468800, while the sum is 79.

The spelling of 9764568778561 in words is "nine trillion, seven hundred sixty-four billion, five hundred sixty-eight million, seven hundred seventy-eight thousand, five hundred sixty-one".