216665566612 has 24 divisors (see below), whose sum is σ = 414302545440. Its totient is φ = 98325233760.

The previous prime is 216665566589. The next prime is 216665566619.

216665566612 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 216665566612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216665566619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3950323 + ... + 4004794.

It is an arithmetic number, because the mean of its divisors is an integer number (17262606060).

Almost surely, 2^216665566612 is an apocalyptic number.

216665566612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

216665566612 is a deficient number, since it is larger than the sum of its proper divisors (197636978828).

216665566612 is a wasteful number, since it uses less digits than its factorization.

216665566612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7955751 (or 7955749 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 52.

The spelling of 216665566612 in words is "two hundred sixteen billion, six hundred sixty-five million, five hundred sixty-six thousand, six hundred twelve".