15543113561 has 2 divisors, whose sum is σ = 15543113562. Its totient is φ = 15543113560.

The previous prime is 15543113543. The next prime is 15543113563. The reversal of 15543113561 is 16531134551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11999887936 + 3543225625 = 109544^2 + 59525^2 .

It is a cyclic number.

It is not a de Polignac number, because 15543113561 - 2⁶ = 15543113497 is a prime.

Together with 15543113563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15543113563) 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, 7771556780 + 7771556781.

It is an arithmetic number, because the mean of its divisors is an integer number (7771556781).

Almost surely, 2^15543113561 is an apocalyptic number.

It is an amenable number.

15543113561 is a deficient number, since it is larger than the sum of its proper divisors (1).

15543113561 is an equidigital number, since it uses as much as digits as its factorization.

15543113561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27000, while the sum is 35.

The spelling of 15543113561 in words is "fifteen billion, five hundred forty-three million, one hundred thirteen thousand, five hundred sixty-one".