16666855517 has 16 divisors (see below), whose sum is σ = 18080764800. Its totient is φ = 15272183232.

The previous prime is 16666855507. The next prime is 16666855519. The reversal of 16666855517 is 71555866661.

It is a cyclic number.

It is not a de Polignac number, because 16666855517 - 2⁴ = 16666855501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16666855519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1021808 + ... + 1037990.

It is an arithmetic number, because the mean of its divisors is an integer number (1130047800).

Almost surely, 2^16666855517 is an apocalyptic number.

It is an amenable number.

16666855517 is a deficient number, since it is larger than the sum of its proper divisors (1413909283).

16666855517 is a wasteful number, since it uses less digits than its factorization.

16666855517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16772.

The product of its digits is 9072000, while the sum is 56.

The spelling of 16666855517 in words is "sixteen billion, six hundred sixty-six million, eight hundred fifty-five thousand, five hundred seventeen".