16851369821764 has 9 divisors (see below), whose sum is σ = 29489911555741. Its totient is φ = 8425680805840.

The previous prime is 16851369821753. The next prime is 16851369821779. The reversal of 16851369821764 is 46712896315861.

The square root of 16851369821764 is 4105042.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5087018615364 + 11764351206400 = 2255442^2 + 3429920^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16851369821764.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7183824 + ... + 9236344.

Almost surely, 2^{16851369821764} is an apocalyptic number.

16851369821764 is the 4105042-nd square number.

It is an amenable number.

16851369821764 is a deficient number, since it is larger than the sum of its proper divisors (12638541733977).

16851369821764 is an frugal number, since it uses more digits than its factorization.

16851369821764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4105046 (or 2052523 counting only the distinct ones).

The product of its digits is 104509440, while the sum is 67.

The spelling of 16851369821764 in words is "sixteen trillion, eight hundred fifty-one billion, three hundred sixty-nine million, eight hundred twenty-one thousand, seven hundred sixty-four".