16551083561 has 2 divisors, whose sum is σ = 16551083562. Its totient is φ = 16551083560.

The previous prime is 16551083557. The next prime is 16551083569. The reversal of 16551083561 is 16538015561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16549536025 + 1547536 = 128645^2 + 1244^2 .

It is an emirp because it is prime and its reverse (16538015561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16551083561 - 2² = 16551083557 is a prime.

It is not a weakly prime, because it can be changed into another prime (16551083569) 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, 8275541780 + 8275541781.

It is an arithmetic number, because the mean of its divisors is an integer number (8275541781).

Almost surely, 2^16551083561 is an apocalyptic number.

It is an amenable number.

16551083561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16551083561 is an equidigital number, since it uses as much as digits as its factorization.

16551083561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108000, while the sum is 41.

The spelling of 16551083561 in words is "sixteen billion, five hundred fifty-one million, eighty-three thousand, five hundred sixty-one".