16556660117 has 2 divisors, whose sum is σ = 16556660118. Its totient is φ = 16556660116.

The previous prime is 16556660083. The next prime is 16556660171. The reversal of 16556660117 is 71106665561.

Together with next prime (16556660171) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16537702801 + 18957316 = 128599^2 + 4354^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556660117 - 2²⁴ = 16539882901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16556665117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278330058 + 8278330059.

It is an arithmetic number, because the mean of its divisors is an integer number (8278330059).

Almost surely, 2^16556660117 is an apocalyptic number.

It is an amenable number.

16556660117 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556660117 is an equidigital number, since it uses as much as digits as its factorization.

16556660117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 226800, while the sum is 44.

The spelling of 16556660117 in words is "sixteen billion, five hundred fifty-six million, six hundred sixty thousand, one hundred seventeen".