16557420066611 has 2 divisors, whose sum is σ = 16557420066612. Its totient is φ = 16557420066610.

The previous prime is 16557420066529. The next prime is 16557420066613. The reversal of 16557420066611 is 11666002475561.

16557420066611 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16557420066611 is a prime.

It is a super-2 number, since 2×16557420066611² (a number of 27 digits) contains 22 as substring.

Together with 16557420066613, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16557420066611.

It is not a weakly prime, because it can be changed into another prime (16557420066613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278710033305 + 8278710033306.

It is an arithmetic number, because the mean of its divisors is an integer number (8278710033306).

Almost surely, 2^{16557420066611} is an apocalyptic number.

16557420066611 is a deficient number, since it is larger than the sum of its proper divisors (1).

16557420066611 is an equidigital number, since it uses as much as digits as its factorization.

16557420066611 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1814400, while the sum is 50.

The spelling of 16557420066611 in words is "sixteen trillion, five hundred fifty-seven billion, four hundred twenty million, sixty-six thousand, six hundred eleven".