16556210552657 has 2 divisors, whose sum is σ = 16556210552658. Its totient is φ = 16556210552656.

The previous prime is 16556210552587. The next prime is 16556210552711. The reversal of 16556210552657 is 75625501265561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12255663654481 + 4300546898176 = 3500809^2 + 2073776^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556210552657 - 2⁴⁰ = 15456698924881 is a prime.

It is a super-2 number, since 2×16556210552657² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16556216552657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278105276328 + 8278105276329.

It is an arithmetic number, because the mean of its divisors is an integer number (8278105276329).

Almost surely, 2^{16556210552657} is an apocalyptic number.

It is an amenable number.

16556210552657 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556210552657 is an equidigital number, since it uses as much as digits as its factorization.

16556210552657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900000, while the sum is 56.

The spelling of 16556210552657 in words is "sixteen trillion, five hundred fifty-six billion, two hundred ten million, five hundred fifty-two thousand, six hundred fifty-seven".