6561316369 has 2 divisors, whose sum is σ = 6561316370. Its totient is φ = 6561316368.

The previous prime is 6561316351. The next prime is 6561316457. The reversal of 6561316369 is 9636131656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4447155969 + 2114160400 = 66687^2 + 45980^2 .

It is a cyclic number.

It is not a de Polignac number, because 6561316369 - 2⁷ = 6561316241 is a prime.

It is a super-2 number, since 2×6561316369² = 86101744988214688322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6561316319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280658184 + 3280658185.

It is an arithmetic number, because the mean of its divisors is an integer number (3280658185).

Almost surely, 2^6561316369 is an apocalyptic number.

It is an amenable number.

6561316369 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561316369 is an equidigital number, since it uses as much as digits as its factorization.

6561316369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 524880, while the sum is 46.

The square root of 6561316369 is about 81001.9528715203. The cubic root of 6561316369 is about 1872.1055305255.

The spelling of 6561316369 in words is "six billion, five hundred sixty-one million, three hundred sixteen thousand, three hundred sixty-nine".