16166555565 has 8 divisors (see below), whose sum is σ = 25866488928. Its totient is φ = 8622162960.

The previous prime is 16166555543. The next prime is 16166555591. The reversal of 16166555565 is 56555566161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16166555565 - 2⁷ = 16166555437 is a prime.

It is a super-2 number, since 2×16166555565² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 538885171 + ... + 538885200.

It is an arithmetic number, because the mean of its divisors is an integer number (3233311116).

Almost surely, 2^16166555565 is an apocalyptic number.

16166555565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16166555565 is a deficient number, since it is larger than the sum of its proper divisors (9699933363).

16166555565 is a wasteful number, since it uses less digits than its factorization.

16166555565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077770379.

The product of its digits is 4050000, while the sum is 51.

The spelling of 16166555565 in words is "sixteen billion, one hundred sixty-six million, five hundred fifty-five thousand, five hundred sixty-five".