16556804017 has 4 divisors (see below), whose sum is σ = 17830404340. Its totient is φ = 15283203696.

The previous prime is 16556803973. The next prime is 16556804021. The reversal of 16556804017 is 71040865561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71040865561 = 107 ⋅663933323.

It can be written as a sum of positive squares in 2 ways, for example, as 11105787456 + 5451016561 = 105384^2 + 73831^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556804017 - 2²⁷ = 16422586289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16556807017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 636800142 + ... + 636800167.

It is an arithmetic number, because the mean of its divisors is an integer number (4457601085).

Almost surely, 2^16556804017 is an apocalyptic number.

It is an amenable number.

16556804017 is a deficient number, since it is larger than the sum of its proper divisors (1273600323).

16556804017 is a wasteful number, since it uses less digits than its factorization.

16556804017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273600322.

The product of its (nonzero) digits is 201600, while the sum is 43.

The spelling of 16556804017 in words is "sixteen billion, five hundred fifty-six million, eight hundred four thousand, seventeen".