16565101666 has 4 divisors (see below), whose sum is σ = 24847652502. Its totient is φ = 8282550832.

The previous prime is 16565101621. The next prime is 16565101667. The reversal of 16565101666 is 66610156561.

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., 9886126041 + 6678975625 = 99429^2 + 81725^2 .

It is not an unprimeable number, because it can be changed into a prime (16565101667) 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, 4141275415 + ... + 4141275418.

Almost surely, 2^16565101666 is an apocalyptic number.

16565101666 is a deficient number, since it is larger than the sum of its proper divisors (8282550836).

16565101666 is an equidigital number, since it uses as much as digits as its factorization.

16565101666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8282550835.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 16565101666 in words is "sixteen billion, five hundred sixty-five million, one hundred one thousand, six hundred sixty-six".