3218320561 has 2 divisors, whose sum is σ = 3218320562. Its totient is φ = 3218320560.

The previous prime is 3218320513. The next prime is 3218320571. The reversal of 3218320561 is 1650238123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2474067600 + 744252961 = 49740^2 + 27281^2 .

It is a cyclic number.

It is not a de Polignac number, because 3218320561 - 2⁷ = 3218320433 is a prime.

It is not a weakly prime, because it can be changed into another prime (3218320571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1609160280 + 1609160281.

It is an arithmetic number, because the mean of its divisors is an integer number (1609160281).

Almost surely, 2^3218320561 is an apocalyptic number.

It is an amenable number.

3218320561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3218320561 is an equidigital number, since it uses as much as digits as its factorization.

3218320561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 3218320561 is about 56730.2437946463. The cubic root of 3218320561 is about 1476.4194797826.

Adding to 3218320561 its reverse (1650238123), we get a palindrome (4868558684).

The spelling of 3218320561 in words is "three billion, two hundred eighteen million, three hundred twenty thousand, five hundred sixty-one".