1329222220561 has 9 divisors (see below), whose sum is σ = 1352202459643. Its totient is φ = 1306626161080.

The previous prime is 1329222220549. The next prime is 1329222220577. The reversal of 1329222220561 is 1650222229231.

The square root of 1329222220561 is 1152919.

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

It can be written as a sum of positive squares in only one way, i.e., 330301928961 + 998920291600 = 574719^2 + 999460^2 .

It is not a de Polignac number, because 1329222220561 - 2¹⁹ = 1329221696273 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 1329222220561.

It is not an unprimeable number, because it can be changed into a prime (1329222220661) 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, 68012451 + ... + 68031991.

Almost surely, 2^{1329222220561} is an apocalyptic number.

1329222220561 is the 1152919-th square number.

1329222220561 is the 576460-th centered octagonal number.

It is an amenable number.

1329222220561 is a deficient number, since it is larger than the sum of its proper divisors (22980239082).

1329222220561 is an frugal number, since it uses more digits than its factorization.

1329222220561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39200 (or 19600 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 1329222220561 its reverse (1650222229231), we get a palindrome (2979444449792).

The spelling of 1329222220561 in words is "one trillion, three hundred twenty-nine billion, two hundred twenty-two million, two hundred twenty thousand, five hundred sixty-one".