15504543304561 has 2 divisors, whose sum is σ = 15504543304562. Its totient is φ = 15504543304560.

The previous prime is 15504543304543. The next prime is 15504543304577. The reversal of 15504543304561 is 16540334540551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15388603054561 + 115940250000 = 3922831^2 + 340500^2 .

It is a cyclic number.

It is not a de Polignac number, because 15504543304561 - 2¹⁷ = 15504543173489 is a prime.

It is not a weakly prime, because it can be changed into another prime (15504543304501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7752271652280 + 7752271652281.

It is an arithmetic number, because the mean of its divisors is an integer number (7752271652281).

Almost surely, 2^{15504543304561} is an apocalyptic number.

It is an amenable number.

15504543304561 is a deficient number, since it is larger than the sum of its proper divisors (1).

15504543304561 is an equidigital number, since it uses as much as digits as its factorization.

15504543304561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160000, while the sum is 46.

The spelling of 15504543304561 in words is "fifteen trillion, five hundred four billion, five hundred forty-three million, three hundred four thousand, five hundred sixty-one".