16556500665 has 96 divisors (see below), whose sum is σ = 30792213504. Its totient is φ = 8210442240.

The previous prime is 16556500661. The next prime is 16556500673. The reversal of 16556500665 is 56600565561.

It is not a de Polignac number, because 16556500665 - 2² = 16556500661 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16556500665.

It is not an unprimeable number, because it can be changed into a prime (16556500661) 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 in 95 ways as a sum of consecutive naturals, for example, 6197280 + ... + 6199950.

It is an arithmetic number, because the mean of its divisors is an integer number (320752224).

Almost surely, 2^16556500665 is an apocalyptic number.

16556500665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16556500665 is a deficient number, since it is larger than the sum of its proper divisors (14235712839).

16556500665 is a wasteful number, since it uses less digits than its factorization.

16556500665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2871 (or 2868 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The spelling of 16556500665 in words is "sixteen billion, five hundred fifty-six million, five hundred thousand, six hundred sixty-five".