16556510005121 has 2 divisors, whose sum is σ = 16556510005122. Its totient is φ = 16556510005120.

The previous prime is 16556510005109. The next prime is 16556510005129. The reversal of 16556510005121 is 12150001565561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15192377107600 + 1364132897521 = 3897740^2 + 1167961^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556510005121 - 2³⁸ = 16281632098177 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16556510005129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278255002560 + 8278255002561.

It is an arithmetic number, because the mean of its divisors is an integer number (8278255002561).

Almost surely, 2^{16556510005121} is an apocalyptic number.

It is an amenable number.

16556510005121 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556510005121 is an equidigital number, since it uses as much as digits as its factorization.

16556510005121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45000, while the sum is 38.

The spelling of 16556510005121 in words is "sixteen trillion, five hundred fifty-six billion, five hundred ten million, five thousand, one hundred twenty-one".