13561221073 has 2 divisors, whose sum is σ = 13561221074. Its totient is φ = 13561221072.

The previous prime is 13561221041. The next prime is 13561221097. The reversal of 13561221073 is 37012216531.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11769646144 + 1791574929 = 108488^2 + 42327^2 .

It is an emirp because it is prime and its reverse (37012216531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13561221073 - 2⁵ = 13561221041 is a prime.

It is not a weakly prime, because it can be changed into another prime (13561228073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6780610536 + 6780610537.

It is an arithmetic number, because the mean of its divisors is an integer number (6780610537).

Almost surely, 2^13561221073 is an apocalyptic number.

It is an amenable number.

13561221073 is a deficient number, since it is larger than the sum of its proper divisors (1).

13561221073 is an equidigital number, since it uses as much as digits as its factorization.

13561221073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 31.

The spelling of 13561221073 in words is "thirteen billion, five hundred sixty-one million, two hundred twenty-one thousand, seventy-three".