16655555666 has 4 divisors (see below), whose sum is σ = 24983333502. Its totient is φ = 8327777832.

The previous prime is 16655555617. The next prime is 16655555669. The reversal of 16655555666 is 66655555661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16389376441 + 266179225 = 128021^2 + 16315^2 .

It is not an unprimeable number, because it can be changed into a prime (16655555669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4163888915 + ... + 4163888918.

Almost surely, 2^16655555666 is an apocalyptic number.

16655555666 is a deficient number, since it is larger than the sum of its proper divisors (8327777836).

16655555666 is an equidigital number, since it uses as much as digits as its factorization.

16655555666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8327777835.

The product of its digits is 24300000, while the sum is 56.

The spelling of 16655555666 in words is "sixteen billion, six hundred fifty-five million, five hundred fifty-five thousand, six hundred sixty-six".