7787342317561 has 9 divisors (see below), whose sum is σ = 7797146789901. Its totient is φ = 7777550168832.

The previous prime is 7787342317537. The next prime is 7787342317577. The reversal of 7787342317561 is 1657132437877.

The square root of 7787342317561 is 2790581.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1093841965161 + 6693500352400 = 1045869^2 + 2587180^2 .

It is not a de Polignac number, because 7787342317561 - 2⁹ = 7787342317049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7787342317561.

It is not an unprimeable number, because it can be changed into a prime (7787342317061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3396135931 + ... + 3396138223.

Almost surely, 2^{7787342317561} is an apocalyptic number.

7787342317561 is the 2790581-st square number.

7787342317561 is the 1395291-st centered octagonal number.

It is an amenable number.

7787342317561 is a deficient number, since it is larger than the sum of its proper divisors (9804472340).

7787342317561 is an frugal number, since it uses more digits than its factorization.

7787342317561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7020 (or 3510 counting only the distinct ones).

The product of its digits is 41489280, while the sum is 61.

The spelling of 7787342317561 in words is "seven trillion, seven hundred eighty-seven billion, three hundred forty-two million, three hundred seventeen thousand, five hundred sixty-one".