1111232321561 has 2 divisors, whose sum is σ = 1111232321562. Its totient is φ = 1111232321560.

The previous prime is 1111232321557. The next prime is 1111232321627. The reversal of 1111232321561 is 1651232321111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1085672305936 + 25560015625 = 1041956^2 + 159875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111232321561 - 2² = 1111232321557 is a prime.

It is not a weakly prime, because it can be changed into another prime (1111232321531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555616160780 + 555616160781.

It is an arithmetic number, because the mean of its divisors is an integer number (555616160781).

Almost surely, 2^{1111232321561} is an apocalyptic number.

It is an amenable number.

1111232321561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111232321561 is an equidigital number, since it uses as much as digits as its factorization.

1111232321561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 29.

Adding to 1111232321561 its reverse (1651232321111), we get a palindrome (2762464642672).

The spelling of 1111232321561 in words is "one trillion, one hundred eleven billion, two hundred thirty-two million, three hundred twenty-one thousand, five hundred sixty-one".