6696312561 has 9 divisors (see below), whose sum is σ = 9672806091. Its totient is φ = 4464044712.

The previous prime is 6696312547. The next prime is 6696312583. The reversal of 6696312561 is 1652136966.

The square root of 6696312561 is 81831.

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

6696312561 is a `hidden beast` number, since 6 + 6 + 9 + 631 + 2 + 5 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1402877025 + 5293435536 = 37455^2 + 72756^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 6696312561 - 2⁷ = 6696312433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6696312061) 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, 231855 + ... + 259131.

Almost surely, 2^6696312561 is an apocalyptic number.

6696312561 is the 81831-st square number.

6696312561 is the 40916-th centered octagonal number.

It is an amenable number.

6696312561 is a deficient number, since it is larger than the sum of its proper divisors (2976493530).

6696312561 is an frugal number, since it uses more digits than its factorization.

6696312561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54560 (or 27280 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The cubic root of 6696312561 is about 1884.8577181314.

It can be divided in two parts, 66963 and 12561, that added together give a square (79524 = 282²).

The spelling of 6696312561 in words is "six billion, six hundred ninety-six million, three hundred twelve thousand, five hundred sixty-one".