1666220722016 has 48 divisors (see below), whose sum is σ = 3475767335040. Its totient is φ = 783554795520.

The previous prime is 1666220722009. The next prime is 1666220722051. The reversal of 1666220722016 is 6102270226661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 294320 + ... + 1849071.

It is an arithmetic number, because the mean of its divisors is an integer number (72411819480).

Almost surely, 2^{1666220722016} is an apocalyptic number.

1666220722016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1666220722016 is an abundant number, since it is smaller than the sum of its proper divisors (1809546613024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666220722016 is a wasteful number, since it uses less digits than its factorization.

1666220722016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2144847 (or 2144839 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

Adding to 1666220722016 its reverse (6102270226661), we get a palindrome (7768490948677).

The spelling of 1666220722016 in words is "one trillion, six hundred sixty-six billion, two hundred twenty million, seven hundred twenty-two thousand, sixteen".