16561884123787 has 2 divisors, whose sum is σ = 16561884123788. Its totient is φ = 16561884123786.

The previous prime is 16561884123751. The next prime is 16561884123791. The reversal of 16561884123787 is 78732148816561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16561884123787 - 2¹⁵ = 16561884091019 is a prime.

It is not a weakly prime, because it can be changed into another prime (16561884123797) 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, 8280942061893 + 8280942061894.

It is an arithmetic number, because the mean of its divisors is an integer number (8280942061894).

Almost surely, 2^{16561884123787} is an apocalyptic number.

16561884123787 is a deficient number, since it is larger than the sum of its proper divisors (1).

16561884123787 is an equidigital number, since it uses as much as digits as its factorization.

16561884123787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108380160, while the sum is 67.

The spelling of 16561884123787 in words is "sixteen trillion, five hundred sixty-one billion, eight hundred eighty-four million, one hundred twenty-three thousand, seven hundred eighty-seven".